UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2021

or

Commission File Number 001-39615

CODIAK BIOSCIENCES, INC.

(Exact name of Registrant as specified in its Charter)

Registrant’s telephone number, including area code: (617) 949-4100

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. YES ☐ No ☒

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. YES ☐ No ☒

Indicate by check mark whether the Registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ NO ☐

Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files). Yes ☒ NO ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☐

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). YES ☐ NO ☒

The aggregate market value of the voting and non-voting common equity held by non-affiliates of the Registrant, based on the closing price of the shares of common stock on Nasdaq Global Market on June 30, 2021 (the last business day of the registrant’s most recently completed second fiscal quarter), was $412,718,249.

The number of shares of Registrant’s Common Stock outstanding as of March 4, 2022 was 22,493,867.

Table of Contents

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SUMMARY OF THE MATERIAL RISKS ASSOCIATED WITH OUR BUSINESS

Our business is subject to numerous risks and uncertainties that you should be aware of before making an investment decision, including those highlighted in the section entitled “Risk Factors.” These risks include, but are not limited to, the following:

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You should consider carefully the risks and uncertainties described below, in the section entitled “Risk Factors” and the other information contained in this prospectus, including our consolidated financial statements and the related notes, before you decide whether to purchase our common stock. The risks described above are not the only risks that we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also impair our business operations.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K contains express or implied forward-looking statements that are based on our management’s belief and assumptions and on information currently available to our management. Although we believe that the expectations reflected in these forward-looking statements are reasonable, these statements relate to future events or our future operational or financial performance, and involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by these forward-looking statements. Forward-looking statements contained in this Annual Report on Form 10-K include, but are not limited to, statements about:

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In some cases, you can identify forward-looking statements by terminology such as “may,” “should,” “expects,” “intends,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “potential,” “continue” or the negative of these terms or other comparable terminology. These statements are only predictions. You should not place undue reliance on forward-looking statements because they involve known and unknown risks, uncertainties, and other factors, which are, in some cases, beyond our control and which could materially affect results. Factors that may cause actual results to differ materially from current expectations include, among other things, those listed above under “Summary of the Material Risks Associated with Our Business” and under the section titled “Risk Factors” and elsewhere in this Annual Report on Form 10-K. If one or more of these risks or uncertainties occur, or if our underlying assumptions prove to be incorrect, actual events or results may vary significantly from those implied or projected by the forward-looking statements. No forward-looking statement is a guarantee of future performance. You should read this Annual Report on Form 10-K and the documents that we reference in this Annual Report on Form 10-K and have filed with the Securities and Exchange Commission as exhibits hereto completely and with the understanding that our actual future results may be materially different from any future results expressed or implied by these forward-looking statements.

The forward-looking statements in this Annual Report on Form 10-K represent our views as of the date of this Annual Report on Form 10-K. We anticipate that subsequent events and developments will cause our views to change. However, while we may elect to update these forward-looking statements at some point in the future, we have no current intention of doing so except to the extent required by applicable law. You should therefore not rely on these forward-looking statements as representing our views as of any date subsequent to the date of this Annual Report on Form 10-K.

This Annual Report on Form 10-K also contains estimates, projections and other information concerning our industry, our business and the markets for our product candidates. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties and actual events or circumstances may differ materially from events and circumstances that are assumed in this information. Unless otherwise expressly stated, we obtained this industry, business, market, and other data from our own internal estimates and research as well as from reports, research surveys, studies, and similar data prepared by market research firms and other third parties, industry, medical and general publications, government data and similar sources. While we are not aware of any misstatements regarding any third-party information presented in this Annual Report on Form 10-K, their estimates, in particular as they relate to projections, involve numerous assumptions, are subject to risks and uncertainties and are subject to change based on various factors, including those discussed under the section titled “Risk Factors” and elsewhere in this Annual Report on Form 10-K.

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PART I

Item 1. Business.

Overview

We are a clinical-stage biopharmaceutical company focused on pioneering the development of exosome-based therapeutics, a new class of medicines with the potential to transform the treatment of a wide spectrum of diseases with high unmet medical need. Exosomes have evolved as a intercellular transfer mechanisms for complex, biologically active macromolecules and have emerged in recent years as a compelling potential drug delivery vehicle. By leveraging our deep understanding of exosome biology, we have developed our engineering and manufacturing platform, or the engEx Platform, to expand upon the innate properties of exosomes to design, engineer and manufacture novel exosome therapeutics. We have utilized our engEx Platform to generate a deep pipeline of engineered exosomes, or engEx exosomes, aimed at treating a broad range of diseases, including oncology, neuro-oncology, infectious disease and rare disease.

In September 2020, we initiated clinical trials of our lead engEx product candidates, exoSTING and exoIL-12, which are being developed to address tumors. In November 2021, we announced that the U.S. Food and Drug Administration, or FDA, cleared our Investigational New Drug Application (IND) for exoASO-STAT6. This will be our first systemically delivered exosome therapeutic candidate. To our knowledge, exoSTING, exoIL-12 and exoASO-STAT6 are the first engineered exosomes to enter clinical development.

In December 2020 and February 2021, we reported positive results from Part A of our Phase 1 clinical trial of exoIL-12 in healthy human volunteers. In this randomized, placebo controlled, double-blind study, exoIL-12 demonstrated a favorable safety and tolerability profile, with no local or systemic treatment-related adverse events and no detectable systemic exposure of IL-12. Results also confirmed retention of active IL-12 at the injection site and prolonged pharmacodynamic effects. These results in healthy volunteers, which are consistent with our preclinical observations, provide validation of our engEx Platform and one of our founding principles – that engineered exosomes can offer the opportunity to tailor therapeutic payloads to provide an active biological response while at the same time limiting unwanted side effects.

In November 2021, we reported initial data from the first three dose escalation cohorts (0.3 mcg, 1.0 mcg, and 3.0 mcg) enrolled in the Phase 1/2 study of exoSTING. Trial participants (n=11) were administered exoSTING intratumorally and all subjects had received at least two prior therapies prior to study entry, with most (73%) having progressed on cancer immunotherapy with checkpoint inhibitors with antibodies that target key inhibitory receptors on T-cells such as Programmed cell Death 1 (PD-1) or its Ligand (PD-L1). Plasma pharmacokinetic, or PK, measurements of subjects that received exoSTING showed no systemic exposure to the agonist. Further, analyses of available plasma biomarkers indicated a lack of systemic inflammatory cytokines detectable in blood after exoSTING administration. exoSTING appeared to be generally well-tolerated. Blood biomarker assessments conducted post-dosing showed evidence of dose-dependent activation of the STING pathway and Type I INF induction along with CXCL10, indicating activation of the innate immune response. Paired tumor biopsies available from two subjects showed evidence of an adaptive immune response and CD8 effector T cell infiltration into the tumor, as well as an increase in PD-L1 expression. Finally, in subjects evaluable for early signs of antitumor activity (n=8), tumor shrinkage was observed in injected as well as distal, non-injected tumors, in a subset of subjects. These observations provide an early indication that exoSTING may both avoid systemic toxicity as well as generate a systemic anti-tumor immune response.

Enrollment in cohorts 4 (6 mcg) and 5 (12 mcg) of the exoSTING trial is ongoing. Data from all five cohorts including objective response data are expected in the late first half of 2022, which will enable identification of a recommended Phase 2 dose. We also expect to receive safety, biomarker and preliminary pharmacodynamics and efficacy results from the treatment of early stage CTCL patients of our Phase 1 clinical trial of exoIL-12 by the late first half of 2022. Furthermore, we also have multiple preclinical and discovery programs that we are advancing either independently or through our strategic collaboration with Jazz Pharmaceuticals Ireland Limited, or Jazz.

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Exosomes are naturally occurring, extracellular vesicles that have evolved as an intercellular messenger system to protect and deliver functional macromolecules, including nucleic acids, proteins, lipids and carbohydrates, between cells. These targeted messengers can transport and protect complex biologically active molecules that can alter the function of recipient cells. The intrinsic immune-silent properties of exosomes, the ability to manipulate cell selectivity, or tropism, through exosome engineering and the ability for exosomes to deliver a broad range of payload options are distinct characteristics that support the potential of exosomes to serve as the foundation of a new class of medicines.

We designed our engEx Platform with two strategic priorities in mind: first, to develop exosome therapeutics engineered to deliver a broad set of biologically active drug molecules on the surface or inside the lumen of the exosome; and second, to manufacture exosomes reproducibly and at scale to pharmaceutical standards.

Our scientists have identified two exosomal proteins, PTGFRN and BASP1, that serve as scaffolds to enable our proprietary exosome engineering methods. Using our engEx Platform, we have demonstrated preclinically our ability to engineer exosomes to incorporate various types of biologically active drug molecules, either on the exosome surface, using PTGFRN as a scaffold, or inside the lumen of the exosome, using BASP1 as a scaffold, to target membrane or cytoplasmic and nuclear drug targets in specific cells. We believe that our engEx exosomes are uniquely positioned to enable specific targeting of critical cells and cellular pathways and thereby reduce off-target toxicity, which together enhance the therapeutic index for a wide array of drug types and therapeutic approaches.

Our current pipeline of engEx product candidates and discovery programs is shown below.

Expanding Pipeline of Proprietary Exosome Therapeutic Candidates

One of our lead clinical stage programs, exoSTING, is an exosome therapeutic candidate engineered with our engEx Platform to deliver our proprietary STING agonist while expressing high levels of PTGFRN on the exosome surface to facilitate specific uptake in tumor-resident antigen-presenting cells, or APCs. In September 2020, we initiated our Phase 1/2 clinical trial of exoSTING. We are developing exoSTING for the treatment of multiple solid tumors. We are also exploring the utility of exoSTING in leptomeningeal disease, and may further expand our activities into this area of high unmet need.

exoSTING has demonstrated encouraging preclinical and early clinical activity. In November 2021, we reported initial clinical data from the first three dose escalation cohorts (0.3 mcg, 1.0 mcg, and 3.0 mcg) enrolled in the Phase 1/2 study. PK measurements in the blood of subjects that received exoSTING showed no systemic exposure to the agonist. exoSTING appeared to be generally well-tolerated. Blood biomarker assessments conducted post-dosing showed evidence of dose-dependent activation of the innate immune response. Paired tumor biopsies available from two subjects showed evidence of an adaptive immune response and CD8 effector T cell infiltration into the tumor, as well as an increase in PD-L1 expression. Finally, in subjects evaluable for early signs of antitumor activity (n=8), tumor shrinkage was observed in injected as well as distal, non-injected tumors, in a subset of subjects. Enrollment in cohorts 4 (6 mcg) and 5 (12 mcg) of the exoSTING trial is ongoing. Data from all five cohorts, including objective response data, are expected in the late first half of 2022, which will enable identification of a recommended Phase 2 dose.

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Our other clinical stage program, exoIL-12, is an exosome engineered using our engEx Platform to display IL-12 in a fully active form on the surface of the engEx exosome. PTGFRN is used as a scaffold to display IL-12 on the exosome surface which enables engagement of the IL-12 receptor on immune effector cells. We are initially focused on cutaneous T cell lymphoma, or CTCL where previous studies with rIL-12 have shown this tumor to be responsive to treatment. In December 2020 and February 2021, we reported positive results from the healthy human volunteer portion of our Phase 1 clinical trial of exoIL-12. In this randomized, placebo controlled, double-blind study, exoIL-12 demonstrated a favorable safety and tolerability profile, with no local or systemic treatment-related adverse events and no detectable systemic exposure of IL-12. Results confirmed the desired localization and retention of IL-12 at the injection site for at least 24 hours, as well as prolonged the production of T cell attractant chemokine IP-10 for 8-15 days depending upon dose. These results are consistent with our preclinical testing and confirm exoIL-12’s target product profile of local drug retention at the injection site, prolonged local pharmacodynamic activity, and lack of systemic IL-12 exposure. We have initiated the next portion of the Phase 1 clinical trial, in which we are evaluating the safety and efficacy of exoIL-12, in CTCL patients at the optimal starting dose of 6 µg administered every other week, which we believe to be the optimal dose based upon prior healthy volunteer data. We expect to see safety, biomarker and preliminary clinical efficacy results in CTCL patients by the late first half of 2022.

Our third clinical stage program, exoASO-STAT6, is an exosome engineered using our engEx Platform to overexpress PTGFRN to selectively target uptake in M2-polarized tumor-associated-macrophages, or TAMs. The drug modality carried by exoASO-STAT6 is an antisense oligonucleotide, or ASO, targeting the STAT6 transcription factor and is linked to the exosome surface. We plan to initially develop exoASO-STAT6, which we believe has unique profile because of its single agent preclinical activity, for primary cancers of the liver. In November 2021, we announced that the FDA had cleared our IND for exoASO-STAT6 which will allow us to begin dosing study subjects in the first half of 2022.

We have entered into a strategic collaboration with Jazz to initiate new programs and bolster our engEx Platform, while retaining meaningful economics and commercialization rights. Our collaboration with Jazz is focused on the research, development and commercialization of exosome therapeutics to treat cancer, directed at up to five targets to be developed using our engEx Platform. As part of the agreement, Jazz paid us an upfront payment of $56.0 million. We are eligible to receive up to approximately $200.0 million in milestone payments per target plus tiered royalties on worldwide sales.

Pursuant to our Manufacturing Services Agreement with Lonza, which closed on November 15, 2021, Lonza became our exclusive manufacturing partner for future clinical and commercial manufacturing of our exosome products pipeline. We and Lonza also entered into a Licensing and Collaboration Agreement, or the License. Pursuant to the License, we granted Lonza a worldwide, exclusive and sub-licensable license to our high-throughput exosome manufacturing intellectual property in the contract development and manufacturing field. Pursuant to the License, we are eligible to receive from Lonza a double-digit percentage of future sublicensing revenues. We will retain our pipeline of therapeutic candidates and core exosome engineering, drug-loading expertise and related intellectual property. We and Lonza will collaborate to establish a joint Center of Excellence for further development of exosome manufacturing technology, with a shared oversight committee. The Center of Excellence will leverage our combined strengths to pursue developments in exosome production, purification and analytics.

We previously had a research collaboration with Sarepta Therapeutics, Inc. or Sarepta, which was terminated effective as of December 3, 2021. As part of the agreement, Sarepta paid us an upfront payment of $10.0 million and provided funding for activities conducted under the research collaboration. Upon termination, the rights previously granted to Sarepta reverted to us.

On October 16, 2020, we completed our initial public offering, or our IPO, pursuant to which we issued and sold 5,500,000 shares of our common stock at a public offering price of $15.00 per share, resulting in net proceeds of $74.4 million, after deducting underwriting discounts and commissions and other offering expenses. On February 17, 2021, we issued and sold an additional 3,162,500 shares of our common stock at a public offering price of $21.00 per share, resulting in net proceeds of $62.0 million, after deducting underwriting discounts and commissions and other offering expenses.

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Our strategy

Our vision is to establish Codiak as a leader in the emerging field of exosomal therapeutics by building a fully integrated biopharmaceutical company utilizing our novel engEx Platform to pioneer the discovery, development and commercialization of engineered exosome therapeutics that can have a transformative impact on the treatment of a wide spectrum of diseases with high unmet medical need. To achieve our vision, we are executing a strategy with the following key elements:

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Our pipeline

Our engEx Platform has generated a broad pipeline of engEx product candidates that we believe can have a transformative impact on the treatment of a wide spectrum of diseases with high unmet medical need, including in oncology, neuro-oncology, neuromuscular disease, infectious disease and rare disease.

Our current pipeline of engEx product candidates and discovery programs is shown below.

Expanding Pipeline of Proprietary Exosome Therapeutic Candidates

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Our focus—leveraging innate properties of exosomes for targeted therapeutic delivery

Exosomes are naturally occurring, extracellular vesicles that have evolved as an intercellular messenger system to protect and deliver functional macromolecules, including nucleic acids, proteins, lipids and carbohydrates, between cells. They can be found in all tissues and biological fluids and it is believed that all cells have the capacity to make, secrete and receive exosomes. Exosomes can promote a change in the biological functions of recipient cells either by protein-to-protein signaling at the target cell surface or according to molecular instructions contained in the interior, or lumen, of the exosome and conveyed by cellular uptake into the cytoplasm or nucleus of the recipient cell where those molecules can engage with the appropriate signaling pathways.

Based on scientific literature, exosomes are known to facilitate maintenance of homeostasis by transmitting messages between cells, both in the local environment as well as systemically. In contrast, during disease, the quantity and composition of exosomes change and exosomes can play important roles in a broad range of diseases, either accentuating or alleviating disease, as well as in altering response to disease treatment.

Exosomes have emerged in recent years as a potential drug delivery vehicle to capitalize on their evolution as intercellular transfer mechanisms for complex, biologically active macromolecules. The size, structure and many functions of exosomes are similar to viruses and their natural capacity to deliver functional nucleic acid payloads has made exosomes an attractive non-viral system to optimize delivery of nucleic acids and numerous other payloads, such as peptides, proteins, antibodies, growth factors, enzymes, small molecules and vaccine antigens. Moreover, based upon available preclinical and early clinical experience, exosomes are believed to be intrinsically “immune-silent”, meaning that the body does not recognize them as foreign and does not elicit an immune-response against them, thus potentially allowing for repeat dosing of allogeneic exosomes. This property of repeat dosing of allogeneic exosomes is supported by our preclinical data as well as a number of clinical trials conducted by others in the past several years. In fact, even though blood products are typed for ABO, they contain large numbers of allogeneic exosomes and single or multiple doses have not been associated with unwanted immune-response.

We believe that exosome-based therapies have the potential to transform therapeutics across multiple drug types and therapeutic areas. The following distinct characteristics of exosomes support their potential to serve as the foundation of a new class of medicines:

We believe that the inherent properties of exosomes, as harnessed using our engEx Platform, have the potential to overcome many drug delivery challenges and enable the development of novel therapies that can address cellular targets and pathways that have essentially been undruggable with other therapeutic approaches.

Our engEx Platform

The key features and capabilities of our engEx Platform include our ability to:

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We designed our engEx Platform with two strategic priorities in mind and believe our significant investments to achieve these priorities give us a durable competitive advantage. First, we aimed to develop exosome therapeutics engineered to deliver a broad set of biologically active drug molecules on the surface or inside the lumen of the exosome. Second, we focused on manufacturing exosomes reproducibly and at scale to pharmaceutical standards.

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Exosome engineering

Our proprietary engEx Platform enables the precise engineering of novel exosome product candidates. Using our engEx Platform, we have demonstrated preclinically that we can engineer exosomes to incorporate various types of biologically active drug molecules either on the surface or inside the lumen of the exosome to target membrane or cytoplasmic and nuclear drug targets in specific cells. We have also demonstrated preclinically the capacity to alter multiple exosome properties through engineering, simultaneously allowing us to engage multiple pathways with the same engEx exosome, providing modular combinatorial opportunities. Our capacity to purposely modify the tropism of our exosomes to target a specific cell type/tissue, the improved tissue specific delivery afforded by compartmental dosing and our capacity to control retention of the exosome in the desired compartment, all contribute to enhancing the therapeutic index and, we believe, improve our chance of success. We believe that this enhanced therapeutic index is an important characteristic of well-tolerated and clinically active therapeutics and may allow us to drug previously “undruggable” targets by increasing potency while reducing the risk of off target effects.

Altering Tropism to Myeloid Cells

Targeting B cells and T cells

The figure above illustrates rational targeting of exosomes to specific immune cells and immune cell subtypes after intravenous administration in mice in vivo (left panels) and human immune cells in vitro (right panels). Exosomes derived from cell lines engineered to overexpress PTGFRN fused to an anti-CLEC9A antibody showed preferential uptake by Conventional Type 1 Dendritic Cells (cDC1) but not other immune cells (top left panel). Conversely, exosomes derived from cell lines engineered to overexpress PTGFRN fused to CD47 showed reduced uptake in primary human macrophages (top right panel). Exosomes were also targeted to lymphoid cells by overexpressing PTGFRN fusions to an anti-CD3 antibody in the case of T cells (bottom left panel) and CD40L in the case of B cells (bottom right panel). These results suggest that engEx exosomes can be targeted to specific immune cell types for therapeutic applications.

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Exosome tropism and compartmental dosing to expand therapeutic index

The proteins on the exosome surface determine the intrinsic cellular tropism of exosomes, analogous to viral capsid proteins dictating AAV tropism. We have developed a suite of tools, including noninvasive imaging and histological techniques, to enable us to carefully analyze the biodistribution and cellular uptake of our engineered exosomes, where tropism has been purposely modified using our engEx Platform, or unmodified exosomes, which naturally target certain cell types or tissues. This has allowed us to develop an understanding of the influence of route of administration of the exosomes on the pattern of uptake and interaction at the cellular level. We have observed a dramatic difference in tissue distribution with different injection routes in animal models. Imaging studies and histology have also revealed rapid distribution and pronounced tissue retention within body compartments (e.g. lung, subcutaneous space, tumor microenvironment) where exosomes are administered.

We have explored the distribution and cellular uptake of exosomes with numerous administration routes including intravenous, intra-peritoneal, oral, sub-cutaneous, intratumoral, intra-ocular, intra-muscular, inhaled, intra-cranial and intrathecal. Through this experimentation, using proprietary exosome identification and localization techniques developed at Codiak, we have confirmed that we can selectively target specific cell types—purposely direct the tropism of our engEx exosomes—in various tissues by engineering the surface proteome of the exosome. Our strategy involves matching the engineered or natural tropism for specific cell types with compartmental dosing—delivery to specific body compartments—for targeted delivery of our drug payloads. We believe we enhance the therapeutic index in this way by increasing target engagement and reducing the potential for off-target effects. Our preclinical studies and early clinical data have demonstrated selective delivery and pharmacodynamic effects of our engEx product candidates across multiple routes of administration. We believe these data highlight the flexibility and wide range of dosing options available to potentially facilitate the drugging of historically challenging targets by our engEx exosomes.

Customization of Exosome Pharmacokinetics with Compartmental Dosing and Cell Tropism

Systemic, Intravenous (IV) dosing of PTGFRN exosomes targets tissue resident immune cells including immunosuppressive macrophages (M2) and antigen presenting cells such as dendritic cells (DCs), cells mediating tolerance such as LSECs and other macrophages in liver, spleen and bone marrow to enable immune modulation. Compartmental administration of PTGRN exosomes intra nasally (IN) can be detected in lung resident macrophages and pneumocytes. Intramuscular (IM) dosed PTGFRN exosomes engage tissue resident innate immune cells and also drain to regional lymph nodes to interact with antigen presenting cells. Intrathecal (ITh) administration of PTGFRN exosomes enable targeting meningeal macrophages and antigen presenting cells in the CNS. Intratumoral (IT) administration enables targeting tumor resident antigen presenting cells such as DCs and macrophages as well as tumor cells. Intra-peritoneal administration enables targeting Immune cells via the lymphatics and tumors such as Pancreatic Adeno Carcinoma in the peritoneum. Direct injection into the macrophage poor compartment of the brain and eye shows uptake into neurons.

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Manufacturing

Our proprietary manufacturing process is based on advanced biochemical engineering principles and is supported by a comprehensive set of methods for analytical characterization of both process and product. Our process format and technologies are designed to support scaling up or down to meet the demands of large or small patient populations, respectively. We have manufactured and released GMP engEx exosomes for our first three clinical programs, exoSTING, exoIL-12 and exoASO-STAT6, from contract manufacturing organizations, or CMOs, and our clinical manufacturing facility using our production technology, which we believe is sufficient to support all phases of planned clinical development.

We developed, from the ground up, a robust and reproducible exosome manufacturing process, capable of large-scale operation, high productivity, purity and quality, assuring compliance with regulatory requirements, such as GMP. As illustrated below, our approach, which we have licensed to Lonza pursuant to our agreement with them, more closely resembles a well-established monoclonal antibody manufacturing process as compared to the small-scale conventional exosome production method.

Comparison of Large-Scale Manufacturing Technology with Conventional Exosome Production Methods

The figure above compares the large-scale manufacturing platform to the conventional method for producing exosomes. Our large-scale manufacturing platform starts with a well-characterized GMP bank of an engEx human cell line. The cells are expanded and transferred to an industrial scale bioreactor and cultured at high cell density in chemically defined media. The exosome-containing harvest is processed in a sequence of advanced chromatography and filtration steps to high purity. Each production run generates a large amount of GMP material that is ready for further processing to final vial fill. The conventional approach typically utilizes primary human cells grown in adherent T-flask or similar cell culture systems and serum-enriched media. The exosome-containing liquid phase is collected and further processed in a sequence of low-capacity centrifugation steps. Finally, the fraction containing purified exosomes is manually extracted from the centrifuge tubes and stored for further use.

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To complement the external manufacturing supply chain, we established a Phase 1/2 clinical manufacturing facility, or CMF, in Lexington, Massachusetts, which commenced operations in the fourth quarter of 2020, and which we sold to Lonza beginning in November 2021 pursuant to the APA. The CMF incorporates our proprietary processes and, once fully operational, will allow for the production of scalable quantities of engEx exosomes for the initial stages of drug discovery through clinical proof of concept studies for ourselves and our collaboration partners. We believe that the CMF and our relationship with Lonza will further reduce time to IND, enhance the speed with which we can incorporate technological advances into the manufacturing process, significantly reduce the costs of GMP manufacturing and strengthen our intellectual property position in the field. Activities at the CMF will cover all steps of the GMP exosome manufacturing process, including cell banking, upstream and downstream operation, exogenous exosome loading and clean up, as well as final vial fill. GMP products have been tested and released in the CMF by a co-located quality control, or QC, lab, including final vial fill. We also believe that the CMF capacity will be sufficient to support the initial stages of drug discovery through clinical proof of concept studies for ourselves and our collaboration partners.

Pursuant to our APA and MSA with Lonza, Lonza has acquired our exosome manufacturing facility and related assets and became the exclusive manufacturing partner for future clinical and commercial manufacturing of our exosome products pipeline. Additionally, pursuant to the License with Lonza, we granted Lonza a worldwide, exclusive and sub-licensable license to our high-throughput exosome manufacturing intellectual property in the contract development and manufacturing field, and a worldwide, non-exclusive and sub-licensable license to such intellectual property for non-therapeutical uses outside the contract development and manufacturing field. We have retained our pipeline of therapeutic candidates and core exosome engineering, drug-loading expertise and related intellectual property. We and Lonza will collaborate to establish a joint Center of Excellence for further development of exosome manufacturing technology, with a shared oversight committee. The Center of Excellence will leverage the strengths of both companies to pursue developments in exosome production, purification and analytics.

We believe that the manufacturing process has overcome the historical challenges associated with exosome production in all critical technical areas, including cell source, cell culture and purification. Key competitive advantages of the manufacturing process versus conventional methods include:

The integration of these novel technologies into an optimized manufacturing process yields several major advantages:

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Our programs

Our versatile engEx Platform has allowed us to develop several engEx therapeutic candidates that may be capable of treating diseases in a wide range of organs or tissues. We have initiated programs across multiple therapeutic areas with the goal of developing and delivering life changing medicines in diseases characterized by significant unmet need.

Our oncology programs

We believe our engEx Platform has broad therapeutic potential across a range of both solid tumors and hematological cancers. Our initial engEx product candidates focus on two well-validated pathways in oncology, STING agonism and IL-12-engagement. We advanced both candidates into clinical trials in September 2020. In November 2021, we announced that the FDA cleared our IND for exoASO-STAT6, our third engEx clinical candidate. We also have multiple preclinical research programs that explore the applicability of our engEx exosomes across various pathways, drug modalities and cancer indications with high unmet need.

exoSTING for the treatment of solid tumors

Overview

exoSTING is an exosome therapeutic candidate engineered with our engEx Platform to carry our proprietary STING agonist inside the lumen of the exosome while expressing high levels of PTGFRN on the exosome surface to facilitate specific uptake in tumor-resident APCs. The STING pathway is a component of the innate immune system that detects cytoplasmic DNA and helps invoke an inflammatory response. Engagement of the STING pathway has been validated to elicit an anti-tumoral response, yet therapeutic development has been generally limited by non-selective cell delivery, off-target toxicity to important immune cells in the tumor and dose-related toxicity due to leakage of the STING agonist into the circulation. We believe exoSTING has the potential to overcome these limitations.

We are developing exoSTING for the treatment of multiple solid tumors with low levels of T cells and enriched in the target APCs, initially focused on metastatic HNSCC, TNBC, cSCC and ATC. We believe there are approximately 90,000 patients annually in the US with these cancers. exoSTING, which we believe has a best-in-class profile, has demonstrated encouraging preclinical activity. In September 2020, we initiated a Phase 1/2 clinical trial of exoSTING. In November 2021, we reported initial data from the first three dose escalating cohorts (0.3 mcg, 1.0 mcg, and 3.0 mcg) enrolled in the Phase 1/2 study of exoSTING. Trial participants (n=11) were administered exoSTING intratumorally and all subjects had received at least two prior therapies prior to study entry, with most (73%) having progressed on checkpoint inhibitors. PK measurements of subjects that received exoSTING showed no systemic exposure to the agonist. Further, analyses of available plasma biomarkers indicated a lack of systemic inflammatory cytokines detectable in blood after exoSTING administration. exoSTING appeared to be generally well-tolerated. Blood biomarker assessments conducted post-dosing showed evidence of dose-dependent activation of the STING pathway and Type I INF induction along with CXCL10, indicating activation of the innate immune response. Paired tumor biopsies available from two subjects showed evidence of an adaptive immune response and CD8 effector T cell infiltration into the tumor, as well as an increase in PD-L1 expression. Finally, in subjects evaluable for early signs of antitumor activity (n=8), tumor shrinkage was observed in injected as well as distal, non-injected tumors, in a subset of subjects. Enrollment in cohorts 4 (6 mcg) and 5 (12 mcg) of the exoSTING trial is ongoing. Data from all five cohorts including objective response data are expected in the late first half of 2022, which will enable identification of a recommended Phase 2 dose.

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We believe exoSTING may also prove beneficial in certain neuro-oncology indications, such as LMD, should the results of our preclinical investigation support moving forward in those areas. We believe there is also a significant opportunity beyond the initial indications in our Phase 1/2 clinical trial in the numerous myeloid rich solid tumors, which show poor responses to the checkpoint inhibitors, or CPIs. We have generated preclinical data with CPIs and exoIL-12 in combination with exoSTING to further expand options for clinical development with molecules that synergize with or enhance the responses to single agent exoSTING.

exoSTING Design

The figure above illustrates the design of exoSTING. The surface of exoSTING is enriched with PTGFRN (green) to facilitate selective uptake in tumor-resident APCs. The lumen of exoSTING is loaded with our proprietary CDN activator of the STING pathway

Free STING agonists for the treatment of solid tumors and historical challenges

The potential for targeting the STING pathway to elicit anti-tumor responses has been well-validated by several industry-sponsored clinical and preclinical programs investigating free STING agonist, or FSA, molecules. The majority of preclinical and clinical programs targeting the STING pathway to date have administered the FSA molecule, a cyclic di-nucleotide, or CDN, intratumorally, in an attempt to localize innate immune activation to the tumor microenvironment, or TME, where APCs and tumor antigens can be found. However, the ability to utilize FSAs as therapies to activate innate immunity in the TME has generally been hampered by absence of selectivity, poor drug-like activities, a short duration of tumor retention and systemic exposure, causing adverse events.

Injecting increasing doses of FSA intratumorally can cause cell death at the injection site and result in leakage of the FSA out of the tumor and into the blood. It is also likely that the systemic exposure to FSAs and activation of the STING pathway in sites distal to the TME interferes with the establishment of the necessary cytokine/chemokine gradients for productive immune-response to the tumor.

Our approach

We have engineered exoSTING to overcome the therapeutic limitations of FSAs. The role of natural exosomes in activating the STING pathway and in mediating immune surveillance is our primary rationale for developing exoSTING. In our exoSTING construct, a highly potent CDN molecule substitutes for genomic DNA and is designed to significantly enhance innate immune activation to attract T cells by establishment of chemokine gradients, facilitate APC presentation of tumor antigens to T cells and promote adaptive immunity to the tumor. Specifically, exoSTING consists of an exosome engineered with our engEx Platform to express high levels of PTGFRN on the exosome surface, with our proprietary, small molecule STING agonist loaded into the lumen of the exosome. The high-level display of PTGFRN in exoSTING promotes directed delivery of our CDN molecule into APCs in the TME to specifically engage the STING pathway in the desired target cell.

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We designed exoSTING to specifically target tumor resident APCs after intratumoral administration to mimic natural immune surveillance, which we believe can enhance the therapeutic index within the tumor and achieve systemic anti-tumor immunity, consistent with our preclinical results. We believe that specific delivery of exoSTING to APCs in the TME and retention in the tumor will overcome observed challenges to FSAs delivered intratumorally. This proposed advantage of exoSTING versus FSAs is supported by extensive preclinical data in mice and studies in non-human primates. Our own preclinical studies have further validated the potential of the STING pathway and suggest differentiation compared to the FSAs that are in advanced and early clinical testing by numerous biopharmaceutical companies.

Anti-Tumor Response to exoSTING in Primary

and Distant Tumor Sites vs. free STING Agonist

The figure above shows that significant systemic anti-tumor activity was observed with exoSTING. B16F10 tumor cells were implanted both subcutaneously as well as intravenously. The mice were treated with a FSA or exoSTING on days 5, 8 and 11 at different doses as indicated. Primary tumor growth (left panel) of the subcutaneous tumor was measured. The secondary lung tumor burden was also evaluated on day 17 using histopathology. The number of secondary lung tumor nodules as evaluated by histology and complete tumor elimination (CR) of the lung metastasis is plotted (Right panel). Representative mouse lung images from the FSA and exoSTING group are shown. (Red arrow = tumor cells, green arrow = immune cells, ANL = adjacent lung tissue.) *p<0.05 by one-way ANOVA

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exoSTING preclinical data

In our pre-clinical studies using tumor-bearing animal models, we observed that selective delivery of our CDN via exoSTING to APCs in the TME resulted in 100-fold greater activity compared to the FSA alone. exoSTING treatment resulted in significant tumor growth inhibition of not only the injected tumor but the distal non-injected lesions in the lung. In our mouse models, we observed that exoSTING, with the selective delivery of our CDN molecule to APCs in the TME, resulted in superior localized anti-tumor immune-response, indicated by interferon beta, or IFNß, production, T cell attracting chemokine release and influx and preservation/expansion of CD8+ T cells, compared to the delivery of FSAs intratumorally. See the figure below. The pattern of innate immune activation followed by adaptive immunity seen preclinically with exoSTING recapitulates the cadence of events noted for natural immune surveillance.

exoSTING Induced CD8+ T cell Recruitment to the Tumor

The figure above shows the immune histochemistry analysis of B16F10 tumors treated with intratumoral injection of either exoSTING or FSA. Samples were harvested at four hours or 24 hours following the first dose or the second dose of indicated treatment and the tumor samples were stained for macrophages and CD8+ T cells using immunohistochemistry. The left panel shows that injection of exoSTING lead to influx and enhancement of both CD8+ T cells as well as macrophages, whereas injection of FSA failed to recruit these immune cells. The number of CD8+ T cells was quantified and plotted (right panel). A statistically significant increase in number of CD8+ T cells was observed at both four hours and 24 hours following the second dose of exoSTING. In contrast, FSA treatment was not associated with sustained increase in CD8+ T cell infiltration. These results suggest that exoSTING mobilizes T cell infiltration into tumors with low levels of T cells.

Other published preclinical studies involving intratumoral administration of competitor FSAs have generated complex dose response curves with activity at low doses, but lack of anti-tumor immune-responses and systemic immune memory at higher doses. The loss of antitumor activity correlates with doses of FSAs that ablate infiltrating T cells in the tumor. In vitro studies with purified human immune cells showed selectivity of exoSTING uptake into APCs, but not T cells, B cells or NK cells, further demonstrating the cell type selectivity of exoSTING compared to FSAs, which demonstrated promiscuous uptake into immune cells. Therefore, we believe the selective targeting to APCs in the TME we have observed in preclinical studies with exoSTING suggests a substantial advantage, as noted in the figure below.

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The potential killing of immune effector cells by FSAs may limit their clinical benefit—the higher the dose, the greater the off-target toxicity, thus resulting in a reduced therapeutic index. We believe that exoSTING and the engineered tropism into APCs in the TME provide an enhanced therapeutic index and potential best-in-class drug phenotype to engage the STING pathway and elicit potent innate and adaptive immune activation in the TME.

Our good laboratory practice, or GLP, toxicology study in non-human primates supports the target product profile of exoSTING as illustrated by dose dependent injection-site retention with potent local pharmacology and limited systemic exposure. See panel A in the figure below. The tissue retained PK profile of exoSTING was correlated with dose dependent and localized pharmacodynamic, or PD, activity as shown by multifold increments in the T-cell attracting chemokine CXCL10 (also known as IP10) with limited systemic IFNß. See panels B and C in the figure below. Local administration of exoSTING was well-tolerated and no local or systemic adverse events were observed. The highest tested dose of 5 µg (approximately 1.6 µg/kg) was the no-observed adverse event level, or NOAEL.

Pharmacokinetic and Pharmacodynamics of exoSTING in Skin and Blood in Non-Human Primates (NHP)

The figure above shows analyses of PK and PD in NHP following subcutaneous administration of exoSTING. Left panel: A 30-minute NHP skin biopsy (n=10) from the injection site was analyzed for exoSTING levels and compared to exoSTING levels in plasma (n=10). Graph represents Mean with SEM of plasma and skin concentrations of exoSTING demonstrating local retention of the drug. Middle panel: Pharmacodynamic (PD) analysis was performed in skin punch biopsy around the injection sites and corresponding plasma at 24 hours post-dose. Transcriptional profiling analysis of the skin samples demonstrated a dose dependent increase in the T-cell attracting chemokine CXCL10 (also known as IP10). Right panel: In contrast, modest increase in IFN levels was observed in plasma. These data show that retention of exoSTING at the injection site led to local pharmacological activity with minimal leakage into blood circulation.

In addition, our approach to the clinical development of exoSTING has been informed by observations from clinical testing by others of FSAs. For example, clinical trials of FSAs with anti-PD-1 checkpoint inhibitors have shown clinical activity in Parotid Gland tumors, TNBC and ATC and clinical trials using FSAs. However, data from clinical trials of FSAs administered as a monotherapy have only shown relatively minimal activity to date. We believe that the properties of exoSTING as opposed to FSAs will have the potential to improve the likelihood of seeing single agent activity, particularly in these tumor types.

Our Phase 1/2 clinical trial

In September 2020, we initiated a Phase 1/2 clinical trial of exoSTING in the US and UK in patients with advanced/metastatic, recurrent, injectable solid tumors, with a focus on tumors likely to be enriched in the target APCs. Examples of such tumors include HNSCC, TNBC, ATC and cSCC.

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In our Phase 1/2 clinical trial of exoSTING, in Part A, we investigated safety, tolerability, pharmacological activity and objective tumor response. Pharmacodynamic and anti-tumor activity were assessed via serial assessment of objective response rate via CT scans and measurement of cancer biomarkers, cytokines, transcriptional profiling analysis in blood and tissue, systemic tumor specific T-cells as well as histological assessment of tumor tissue biopsies for histological response (e.g. T cell infiltration) and biomarkers. Our analyses characterized safety, retention of our CDN molecule, dose response and objective tumor responses and, assuming positive data, should define a dose to advance into potential cohort expansion studies. We plan to enroll expansion cohorts of patients at the recommended Phase 2 dose in Part B of the trial.

Outline of Our exoSTING Phase 1/2 Clinical Trial

The figure above outlines flow of our exoSTING Phase 1/2 clinical trial. The study design is open label and multiple dose cohorts will be investigated using a common oncology “3+3” design. Subjects with injectable solid tumors can be enrolled with particular focus on patients with HNSCC, TNBC, cSCC and ATC. During screening study subjects will have a pre-dose biopsy of the injected tumor lesion(s) as well as CT scanning (imaging) for estimating tumor burden and establishing baseline for assessment of clinical activity. During Cycle 1, exoSTING will be dosed on Days 1, 8 and 15. During Cycle 2, exoSTING will be dosed on Days 1 and 15. From Cycle 3 and onwards, exoSTING will be dosed on Day 1 of each cycle. Safety data and samples will be collected throughout the study. Following start of treatment with exoSTING, serial tumor biopsies are taken on Cycle 1 Day 15 and Cycle 2 Day 15. CT scanning Imaging for assessment of anti-tumor activity via RECIST is done at eight-week intervals throughout the study. Following completion of Part A, the study can transition to Part B with potential early expansion into the initial target indications.

We initiated this trial in September 2020. We have made a number of trial design enhancements to include patients with cutaneous Squamous Cell Carcinoma (cSSC), HNSCC or TNBC for our exoSTING Phase 1/2 program based upon observations from clinical testing of FSAs (ADUS100 and MK 1454) and other intratumoral administered drugs. We believe these enhancements will reduce variability with dosing and optimize the assessment timing for biomarkers to provide robust data to evaluate the single agent activity of exoSTING.

In November 2021, we reported initial data from the first three dose escalating cohorts (0.3 mcg, 1.0 mcg, and 3.0 mcg) enrolled in the Phase 1/2 study of exoSTING. Trial participants (n=11) were administered exoSTING intratumorally and all subjects had received at least two prior therapies prior to study entry, with most (73%) having progressed on checkpoint inhibitors. PK measurements of subjects that received exoSTING showed no systemic exposure to the agonist. Further, analyses of available plasma biomarkers indicated a lack of systemic inflammatory cytokines detectable in blood after exoSTING administration. exoSTING appeared to be generally well-tolerated. Blood biomarker assessments conducted post-dosing showed evidence of dose-dependent activation of the STING pathway and Type I INF induction along with CXCL10 (as shown in the figure below), indicating activation of the innate immune response. Paired tumor biopsies available from two subjects showed evidence of an adaptive immune response and three and 11-fold increase in CD8 effector T cell infiltration into the tumor, as well as an increase in PD-L1 expression as shown in the figure below. Finally, in subjects evaluable for early signs of antitumor activity (n=8), 74 to 77% tumor shrinkage was observed in injected as well as distal, non-injected lesions, in a subset of subjects with Parotid Gland tumor and cSSC. Enrollment in cohorts 4 (6 mcg) and 5 (12 mcg) of the exoSTING trial is ongoing. Data from all five cohorts including objective response data are expected in the late first half of 2022, which will enable identification of a recommended Phase 2 dose.

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The figure above illustrates induction of adoptive immune response and reduction on a non-injected lesion in a Parotid Gland tumor patient undergoing exoSTING treatment. The figure shows a 3 fold induction in CD8 T-cells in the tumor biopsy samples collected 6 weeks after exoSTING therapy. Similar induction in PD-L1 was also observed demonstrating effectively adaptive immune response initiation and on-going inflammation in the exoSTING injected tumor.

The figure above illustrates induction of adoptive immune response and reduction on a non-injected lesion in a Parotid Gland tumor patient undergoing exoSTING treatment. The figure shows a 3 fold induction in CD8 T-cells in the tumor biopsy samples collected 6 weeks after exoSTING therapy. Similar induction in PD-L1 was also observed demonstrating effectively adaptive immune response initiation and on-going inflammation in the exoSTING injected tumor.

Our Phase 1/2 study was designed to provide initial data to confirm the expected target product profile as shown above as well as to identify a dose for cohort expansion in select tumors, and/or eventual combination studies. We anticipate selecting our recommended Phase 2 Dose (RP2D) in the late first half of 2022.

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Indication expansion opportunities.

Our investigation of exoSTING in LMD would represent a unique area of exploration of this pathway in areas of high unmet need, fits well with standard routes of delivery for drugs in these indications and may provide a potential opportunity for rapid single-agent development should our studies warrant progression into these malignancies.

The incidence of LMD is increasing and it is now being seen with in 5% of all cancer cases (approximately 110,000 cases per year). The most common cancers to involve LMD are breast cancer, lung cancer, and melanomas. A majority of patients with Melanoma, NSCLC and breast cancer develop metastasis in the brain and rapidly succumb to the disease. The Meninges in the brain provides a sanctuary site for the tumor cells to evade immune surveillance and escape from peripheral therapies. LMD is a rapidly progressing and increasingly lethal disease with limited effective therapies. Currently chemotherapy is administered directly into the CSF as a palliative therapy.

In preclinical testing, we have shown that the high M2 resident macrophage population of the meninges can be targeted with intrathecal exoSTING dosing to activate macrophage IFN signaling. Exosomes when administered directly into the CSF can migrate to the Meninges and could provide a significant benefit in treating these patients with LMD. exoSTING administration into the CSF of a mouse melanoma model of LMD demonstrated a significant dose dependent improvement in survival (see below).

The figure above shows the dose dependent survival benefit provided by administration of exoSTING into the cerebrospinal fluid (CSF) in a leptomeningeal tumor pre-clinical model. Mice bearing B16F10-luc melanoma tumors in the meninges was established and exoSTING was administered directly into the CSF via intra-ventricular administration (ICV). This route of administration is routinely used to administer chemotherapy. exoSTING treatment resulted in a significant dose dependent improvement in survival. ****P<0.0001; ***P<0.0005; **P,0.02 Log-Rank (Mantel-Cox) Test.

Furthermore, we believe there is also a significant opportunity beyond the initial indications in our Phase 1/2 clinical trial in the numerous myeloid rich solid tumors, which show poor responses to the CPIs. Combination therapies of exoSTING with CPIs as well as exoIL-12 could be beneficial for the treatment of tumor types that show limited response to CPI therapy. We have evaluated the combination therapy of exoSTING with CPI and exoIL-12 to further expand options for clinical development with molecules that synergize with or enhance the responses to single agent exoSTING.

In preclinical testing, exoSTING treatment in combination with exoIL-12 and anti-PD-1 dramatically decreased the growth of both injected and distal non-injected tumors in a mouse colorectal cancer model (MC38) resulting in significant improvement in survival. These results demonstrate the potential for the combination therapy to further enhance responses in both distal tumors and provide a significant survival benefit.

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The figure above illustrates the intratumoral combination therapy (n = 5) of exoSTING and exoIL12 along with anti-PD-1. Survival of triple combination (a) was 100% (*** p=0.0003, ** p=0.0018). No tumors grew following subcutaneous rechallenge with MC38 tumor cells in 100% responders 76 days post original tumor inoculation demonstrating lasting immunological memory

exoIL-12 for the treatment of cancer

Overview

exoIL-12 is an exosome engineered using our engEx Platform to display IL-12 in a fully active form on the surface of the engEx exosome, via PTGFRN, which enables engagement of the IL-12 receptor on immune effector cells. In previous preclinical and clinical studies conducted by others, IL-12 was observed to elicit a significant anti-tumor immune-response as a single agent through activation of T cells, NK cells and macrophages. We are developing exoIL-12 for the treatment of various forms of cancer that contain T cells and NK cells and which have previously shown clinical responses to IL-12 in prior studies with recombinant IL-12, or rIL-12. Development of rIL-12 and other strategies that have attempted to localize IL-12 to the TME have been limited by unwanted systemic exposure to IL-12, which has been associated with serious toxicity, including liver function abnormalities, hematologic toxicity and death. We believe exoIL-12 has the potential to overcome these limitations because of the pronounced localization of IL-12 in the TME with undetectable systemic exposure as seen in our preclinical mouse tumor models and non-human primate, or NHP, studies.

We are developing exoIL-12 for the treatment of solid tumors where engagement of the IL-12 pathway has been well-characterized, such as melanoma, MCC, Kaposi sarcoma and TNBC. We are initially focused on early stage CTCL. exoIL-12, which we believe has a best-in-class profile, has demonstrated encouraging preclinical and now clinical activity. In September 2020, we initiated a Phase 1 clinical trial of exoIL-12. In December 2020 and February 2021, we reported positive results from the single ascending dose portion of our Phase 1 clinical trial of exoIL-12 in healthy volunteers. In this randomized, placebo controlled, double-blind study, exoIL-12 demonstrated a favorable safety and tolerability profile, with no local or systemic treatment-related adverse events and no detectable systemic exposure of IL-12. Results confirmed the desired localization and retention of IL-12 at the injection site for at least 24 hours, as well as prolonged production of the T cell attractant chemokine IP-10 for eight to 15 days depending upon dose. These results are consistent with our preclinical testing and confirm exoIL-12’s target product profile of local drug retention at the injection site, prolonged local pharmacodynamic activity, and lack of systemic IL-12 exposure. We have initiated the next portion (Part B) of the Phase 1 clinical trial, evaluating the safety and efficacy of exoIL-12, in CTCL patients at the optimal starting dose of 6 µg administered every other week, which we believe to be the optimal pharmacologically active dose based upon the healthy volunteer data from Part A of the trial and prior preclinical data with exoIL-12. We expect to see safety, biomarker and preliminary efficacy results from the repeat dose portion of our Phase 1 clinical trial of exoIL-12 by the late first half of 2022.

We estimate that the initial target patient populations for exoIL-12 represent approximately 19,000 current patients in the US and UK with an annual incidence rate of 3,600 new cases.

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exoIL-12 Design

The figure above illustrates the design of exoIL-12. The surface of exoIL-12 is enriched by the type I glycoprotein called PTGFRN (green) with in frame fusion of IL-12 (blue and yellow).

IL-12 and historical challenges

Clinical trials to date investigating rIL-12 in patients with CTCL, melanoma, MCC, Kaposi sarcoma, GBM and TNBC have reported encouraging single agent clinical activity data. However, systemic exposure to IL-12, even at low doses, is associated with substantial toxicities and in some cases, fatalities. Several more recent approaches have been tried to localize IL-12 to the TME via intratumoral administration, including adenovirus gene therapy, messenger RNA and electroporation of plasmid DNA encoding soluble rIL-12. These methods all delivered rIL-12, which is not localized to the TME exclusively, and showed wide variability in the quantity and duration of rIL-12 production, leading to variable degrees of systemic exposure and IL-12 induced toxicity. More recently, an adenovirus vector with a controllable promoter was shown to have promising results in GBM. While intra-patient levels of rIL-12 exposure in the systemic circulation could be managed, inter-patient IL-12 production levels varied widely. These observations suggest the level of localized TME dosing may be highly correlated to more robust tumor responses, the ability to control dose and a potentially better overall adverse event profile resulting from controlled systemic exposure. While rIL-12 has demonstrated an encouraging biological rationale as a viable cancer treatment across multiple tumor settings, its utility has been severely limited due to the historical inability to manage adverse events caused by systemic exposure to rIL-12 or consistently deliver precise local dosing in the TME.

Our approach

We designed exoIL-12 to overcome the therapeutic limitations of rIL-12. exoIL-12 was engineered to display IL-12 on the surface of the exosome using PTGFRN as a scaffold to facilitate potent local pharmacology at the injection site, with precisely quantified doses and to minimize the systemic exposure to IL-12. By displaying IL-12 on the surface of an exosome, and administering the drug intratumorally, we believe exoIL-12 may limit systemic exposure of IL-12 and associated toxicity and therefore potentially demonstrate an enhanced therapeutic index. We expect that exoIL-12 will allow local TME pharmacology without systemic exposure to the drug, with the potential to deliver more robust tumor response, dose control and an improved safety profile, and ultimately unlocking the potential of IL-12 across a group of human tumors already shown to be responsive to rIL-12 in prior studies.

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exoIL-12 preclinical data

We have conducted extensive in vitro and in vivo testing of exoIL-12 in animal models. The results in syngeneic tumor models in mice demonstrated that exoIL-12 was approximately 100-fold more potent than rIL-12 despite equipotency in vitro. In vivo rechallenge studies in animals previously treated with exoIL-12 also confirmed the establishment of immunological memory.

Our GLP toxicology study in non-human primates supports the target product profile of exoIL-12 as illustrated by dose dependent injection-site retention and no measurable systemic exposure of IL-12. See the left panel in the figure below. Four weekly doses of exoIL-12 demonstrated dose dependent and sustained localized pharmacodynamic activity as shown by increments in IFNY induced chemokines, such as IP-10, with negligible levels of IFNY and related chemokines in systemic plasma. See middle and right panels in the figure below. In NHPs, local administration of exoIL-12 was generally well-tolerated and no systemic or local adverse events were observed. The highest tested dose of 3 µg (approximately 1 µg/kg) was the NOAEL.

Pharmacokinetics and Pharmacodynamics of exoSTING in skin and blood in NHP

The figure above shows analyses of PK and PD in NHP following subcutaneous administration of exoIL-12. Left panel: A 30-minute NHP skin biopsy (n=10) from the injection site was analyzed for exoIL-12 levels and compared to exoIL-12 levels in plasma (n=10). Graph represents Mean with SEM of plasma and skin concentrations of exoIL-12 demonstrating local retention of the drug. Middle panel: PD analysis was performed in skin punch biopsy around the injection sites and corresponding plasma following repeat dosing. ELISA analysis of the skin samples demonstrated a dose dependent increase in IFNY related chemokine IP-10. Right panel: In contrast, a modest increase in IP-10 levels was observed in plasma. These data show that retention of exoIL-12 at the injection site led to local pharmacological activity with minimal leakage into blood circulation.

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Our Phase 1 clinical trial

We received clearance for our CTA in the UK for exoIL-12 in August 2020 and initiated a Phase 1 clinical trial in September 2020. In addition, we have completed GMP manufacturing of exoIL-12 and vialed material has been released and qualified. Our Phase 1 clinical program for exoIL-12 consists of two parts (Parts A & B) to explore safety, tolerability, PK and PD with a single subcutaneous dose in healthy volunteers (Part A) and a repeat dose study of intra-lesional administered exoIL-12 in stage IA-IIB CTCL patients (Part B).

Outline of Our exoIL-12 Phase 1 Clinical Trial

The figure above outlines the flow of our exoIL-12 Phase 1 clinical trial. Part A of the study was a randomized, placebo-controlled, single ascending dose design in healthy volunteers. exoIL-12 was administered subcutaneously and the study investigated safety and tolerability, as well as PK and PD in blood and within the area of the injected skin. Following completion of Part A in which we identified what we believe to be the optimal pharmacologically active starting dose, 6mg, the study will transition to Part B which will be an open label, “3+3” design, multiple ascending dose study of intra-lesional administration of exoIL-12 in patients with CTCL Stage IA-IIB. During Part B, safety, PK, and clinical activity data will be collected. We intend to assess anti-tumor response at four-week intervals using CAILS and mSWAT scores. We plan to also assess pharmacodynamics in serial blood samples and paired tumor lesion biopsies. Pending the data generated in Parts A and B, we may expand our clinical development of exoIL-12 into multiple other indications, in some of which rIL-12 has proven to have single agent anti-tumor activity, such as TNBC, melanoma, GBM, MCC and Kaposi sarcoma.

Part A was a single ascending dose placebo-controlled investigation of subcutaneously administered exoIL-12. A total of five cohorts each with five subjects were enrolled, randomized 3:2 active drug to placebo, and dosed in Part A of the Phase 1 study. Each cohort received a subcutaneously administered single ascending dose of exoIL-12: 0.3 µg, 1.0 µg, 3.0 µg, 6.0 µg or 12.0 µg, respectively. We compared safety, tolerability and PK/PD data from serial blood and skin punch biopsies against previous single ascending dose studies of rIL-12 in healthy volunteers, which have shown systemic release of rIL-12 into the blood from the injection site and systemic IFNY production. We expected that subcutaneous administration of exoIL-12 would demonstrate a better adverse event profile as well as retention of IL-12 at the injection site and localized pharmacodynamic effects, in contrast to previous studies with subcutaneous administration of rIL-12. We observed this profile of exoIL-12 in our GLP toxicology study where exoIL-12 was administered in animal models by subcutaneous administration.

In December 2020, we reported positive tolerability data from Part A of our randomized, placebo-controlled, double-blind Phase 1 trial of exoIL-12 in healthy human volunteers. Consistent with our expectations and results of our preclinical observations, exoIL-12 demonstrated a favorable safety and tolerability profile, with no local or systemic treatment-related adverse events and no detectable systemic exposure of IL-12. In February 2021, we announced positive pharmacodynamic activity results from Part A of the trial. Results confirmed the desired localization and retention of IL-12 at the injection site for at least 24 hours, as well as prolonged production of the T cell attractant chemokine, IP-10, for eight to 15 days depending upon dose. These results are consistent with our preclinical testing and confirm exoIL-12’s target product profile of local drug retention at the injection site, prolonged local pharmacodynamic activity, and lack of systemic IL-12 exposure. PD measurements including IL-12 receptor-mediated signaling assessed by induction of IP-10 was measured in skin punch biopsies at a 1.5 cm radius from the subcutaneous injection site. Samples were collected immediately prior to dosing (placebo or exoIL-12) and at 24 hours, Day 8 and Day 15 after administration. Results showed detectable IL-12 near the injection site as much as 24 hours post injection at the 6 µg dose. Samples collected at the 8-day and 15-day time points did not have detectable IL-12. In contrast, doses from 1.0 µg to 12 µg (not 0.3 µg) showed significant induction of IP-10 production in the skin detectable for eight to 15 days confirming robust and durable local pharmacology. At the highest 12 µg dose, IP-10 was also detectable in the plasma, but not at any of the

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lower doses. As noted above, no detectable IL-12 was present in plasma and no drug-related adverse events were observed across the entire dose range. These results confirm the prolonged, local activation of the IL-12 signaling cascade. We have initiated the Part B portion of the Phase 1 clinical trial, described below, evaluating the safety and efficacy of exoIL-12, in CTCL patients at the optimal starting dose of 6 µg administered every other week, which we believe to be the optimal pharmacologically active dose based upon this healthy volunteer data and prior preclinical data with exoIL-12.

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Part B is a multiple ascending dose open label clinical trial of intra-lesional administered exoIL-12 and is being conducted in patients with Stage IA-IIB CTCL (Mycosis fungoides, or MF). Exacerbation or progression of CTCL has been associated with reduction in levels of IL-12 within the tumor lesions. As such, the therapeutic rationale of exoIL-12 is to restore the local deficit of IL-12 and prevent progression. Importantly, rIL-12 used by others as a single agent has been clinically validated in CTCL with previous studies conducted by others reporting an overall response rate of 56%, which included two out of nine complete responses and three out of nine partial responses. A follow-on study in 23 patients with Stage IA, IB or IIA CTCL showed measurable response in 17 out of 23 patients (74%) and duration of effect lasting from three to 45 weeks. The clinical activity of rIL-12 was observed after approximately four to six weeks dosing and we believe the cutaneous nature of the disease enables potential early detection of clinical activity using validated assessment measures specific for CTCL. It has also been observed in the trials of rIL-12 conducted by others that treatment effects can be observed in distal lesions and not just the injected lesion. This is consistent with the anticipated systemic immune-response against the malignant cells, supported by our preclinical mouse models showing development of systemic immunological responses to the tumor.

Part B of our trial is investigating safety and IL-12 exposure as well as local biomarker analysis of gene expression in serial punch biopsy specimens. Furthermore, we plan to assess clinical activity at four week intervals via serial assessment of objective response rate using Olsen criteria and Composite assessment of index lesion severity, or CAILS, and Modified Severity Weighted Assessment Tool, or mSWAT. In addition, we plan to obtain serial blood samples for measurements of cytokines and gene expression, assess local lesional responses by histology and analyze cellular biomarkers. We expect that patients will be able to continue to receive exoIL-12 for as long as they are experiencing clinical benefit. The study is being conducted in the UK. Patient enrollment has been initiated and we anticipate initial biomarker and anti-tumor efficacy results as assessed by CAILs, which has been recognized by the FDA as a precedented endpoint for CTCL approval by the FDA, by late first half 2022.

Pending proof of concept data from Part B of our CTCL Stage IA-IIB study, we plan to further develop exoIL-12 in this patient population. We anticipate initially expanding development of exoIL-12 to include other indications where rIL-12 has demonstrated single agent clinical activity, using doses derived from the Phase 1 CTCL study. We believe exoIL-12 may have utility in several other tumor types that have been shown to respond to rIL-12 monotherapy over the last two decades, such as melanoma, MCC, Kaposi sarcoma, GBM and TNBC. As mentioned above in our discussion of exoSTING, we are exploring exoIL-12 as a combination therapy with exoSTING in animal models, which represents a possible proprietary combination strategy in cancer therapy.

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exoASO-STAT6 for treatment of cancer

Overview

exoASO-STAT6 is an exosome engineered using our engEx Platform to overexpress PTGFRN to selectively target uptake in M2 polarized tumor-associated macrophages. exoASO-STAT6 is engineered with a surface displayed antisense oligonucleotide, or ASO, selective for the transcription factor STAT6. STAT6 is a transcription factor that activates genes that encode immunosuppressive cytokines from these M2 macrophages. We are developing exoASO-STAT6 for treatment of cancers rich in so-called M2 polarized (tumor permissive/anti-inflammatory) macrophages. These M2 macrophages secrete cytokines that repel T cells and other immune effector cells from the TME and dampen their function. These M2 macrophages are “polarized” meaning they are biased by the expression of certain gene transcription factors, to make several immune suppressive factors. Targeting STAT6 acts as a potent switch of the polarization of tumor-associated macrophages from an M2 tumor permissive/anti-inflammatory phenotype to an M1 T cell attractive, anti-tumor/inflammatory phenotype. This is reflected in the production of prototypical M1 cytokines (TNF) commensurate with suppression of STAT6 mRNA in vitro and in preclinical models in vivo and a reduction in M2 cytokine production.

We plan to initially develop exoASO-STAT6 for primary and metastatic cancers of the liver, such as HCC. We estimate there to be approximately 42,000 new patients annually in the US with these cancers. We are also exploring the utility of exoASO-STAT6 in GBM and LMD and may further expand our development efforts into these M2 rich, intractable tumors of the central nervous system, or CNS.

exoASO-STAT6 Design

The figure above illustrates the design of exoASO-STAT6. The surface of exoASO-STAT6 is enriched with PTGFRN (blue and green) to facilitate selective uptake in tumor-resident M2 polarized macrophages. exoASO-STAT6 is further loaded with our proprietary ASO targeting STAT6.

Our approach

exoASO-STAT6 is an exosome engineered using our engEx Platform to overexpress PTGFRN to selectively target uptake in M2 polarized tumor associated macrophages to potentially enhance the therapeutic index. exoASO-STAT6 is engineered with a surface displayed ASO, selective for the transcription factor STAT6. We have designed exoASO-STAT6 to allow for the necessary delivery specificity of the STAT6 ASO to the M2 macrophages to repolarize these cells, potentially resulting in strong single agent anti-tumor activity not possible with free ASO and not observed with other pathway inhibitors described above.

Our strategy with exoASO-STAT6 is to reduce the levels of specific transcription factors, such as STAT6, which are known to polarize macrophages in the M2 direction. By “repolarizing” the macrophages to the M1 immune stimulatory phenotype, exoASO-STAT6 is designed to promote an influx of T cells and immune effector cells to control tumor growth. exoASO-STAT6 uses the same exosome construct with high level PTGFRN display engineered onto the surface as exoSTING, thus reducing manufacturing risk. These exosomes are “loaded” with a proprietary ASO-linker system to the exosome surface using proprietary methods of loading. The PTGFRN

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display promotes selective uptake of the construct by M2 macrophages with selective delivery of the ASO to the target cell with limited uptake in non-target cells, thus potentially enhancing the therapeutic index of the candidate.

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exoASO-STAT6 preclinical data

Our in vitro studies showed preferential uptake of engEx exosomes overexpressing PTGFRN into M2 polarized macrophages. Our in vivo biodistribution studies demonstrated that exoASO-STAT6 resulted in up to 12-fold increased selective delivery of ASOs to myeloid cells as compared to free ASO. See figure below. Furthermore, exoASO-STAT6 offered greater activity than free ASO, and in vitro, led to effective M2 to M1 macrophage reprogramming as shown by decrease in classical M2 factors and increase in anti-tumoral cytokines such as IL-12. In vivo studies with exoASO-STAT6 also showed more significant reduction in STAT6 mRNA in the myeloid subset of cells in the TME compared to comparable levels of free ASO, which led to a distinct decrease in expression of M2 genes and increase in expression of M1 genes.

Intravenous administration of exoASO-STAT6 enabled selective targeting of STAT6 in the tumor associated macrophages in a pre-clinical model of Hepatocellular Carcinoma (HCC). The selective macrophage targeting mediated by exosome resulted in improved STAT6 silencing in the liver. exoASO-STAT6 monotherapy resulted in significant tumor growth inhibition in this aggressive model of HCC resulting in complete tumor remission in about 50% of the animals. It is important to note that this model is refractory to other macrophage targeting agents such as anti-CSF1R antibody and checkpoint inhibitors such as anti-PD-1. Combination therapy with exoASO-STAT6 and anti-PD1 further enhanced the anti-tumor activity leading to complete tumor remissions in about 75% of the animals. Therefore, we believe that exoASO-STAT6 has potential to be effective as a monotherapy and as a combination therapy with checkpoint inhibitors in the treatment of myeloid rich tumors.

exoASO-STAT6 Reduces mRNA Transcripts for STAT6 and Repolarizes Macrophages from M2 to M1 in vivo

The figure above shows direct injection of CT26 tumors was performed with 15 g of free ASO or exoASO on Days 8, 10 and 13. After treatment, tumor-associated myeloid cells were isolated using CD11b-positive selection magnetic beads (80% enrichment). Target gene reduction was analyzed by qPCR in total tumor and in tumor CD11b+ cells. Gene expression analysis in tumor myeloid cells was performed by transcriptional profiling using a mouse myeloid panel. The three panels show that exoASO led to selective knockdown of STAT6 in the myeloid cells and that the knockdown leads to down regulation of the M2 marker CSF1R and up regulation of the M1 marker NOS2. ***, P < 0.001 by two-way ANOVA, compared to a scrambled ASO (exoASO-scramble) or free STAT6 ASO. Overall these data demonstrate the ability of the engEx Platform to drug transcription factor biology for reprogramming tumor macrophages for enhanced tumor killing.

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The figure above shows selective targeting of tumor associated macrophages after intravenously (IV) administered exoASO-STAT6 and leading to potent STAT6 mRNA silencing. Panel A shows selective targeting of tumor associated immune-suppressive M2 macrophages by exoASO-STAT6 treatment. 99% of the STAT6 targeting ASO was observed in the tumor resident M2 macrophages as compared to M1 macrophages following IV administration of exoASO-STAT6 in Hepatocellular carcinoma (Hepa 1-6) tumor bearing mice. Panel B shows 80% reduction in STAT6 mRNA expression following 3 doses of exoASOSTAT6 administration. Equivalent dose of free STAT6 ASO treatment resulted in ~35% reduction in STAT6 mRNA levels demonstrating the improved potency and selectivity by exosome mediated delivery. ***P<0.0001 t-test; ****P<0.0001 one-way ANOVA

The figure above shows anti-tumor activity of intravenously administered exoASO-STAT6 and control exosome treatments as single agents and in combination with an anti PD-1 monoclonal antibody evaluated in the orthotopic Hepa1-6 murine hepatocellular carcinoma model. Hepa1-6 tumor cells were surgically implanted in the livers of mice (n=7-8 per group) and the indicated therapeutics were dosed intravenously (starting day 3, every two days for six treatments), while antibody treatments were given intraperitoneally (anti PD-1: twice weekly for four treatments; anti CSF1R: every two days for six treatments). All treatments were terminated on day 16 and tumor burden was determined at the end of the study histologically by scoring of % of macroscopic tumor lesions. exoASO-STAT6 monotherapy and in combination with an anti PD-1 monoclonal antibody resulted in complete tumor remissions (CR) in 50% of mice in each group, significantly more than in any other treatment group. (*** P<0.0005; ** P<0.005 one-way ANOVA).

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exoASO-STAT6 program status and clinical development plan

We have nominated exoASO-STAT6 to be our third wholly owned engEx product candidate to enter the clinic and in November 2021, we announced that the FDA cleared our IND for exoASO-STAT6. We have manufactured GMP exosomes using our proprietary manufacturing technology to support these activities. We expect to dose the first patient in this clinical study in the first half of 2022.

We plan to initially develop IV administered exoASO-STAT6 for HCC. Patients with high levels of STAT6 mRNA transcripts in their tumors have a worse prognosis, and provides a rationale for this population of HCC patients to be treated with exoASO-STAT6. Following completion of our dose escalation we plan to expand testing to liver metastatic disease in PDAC, CRC and other tumors enriched in M2 macrophages and highly enriched for STAT6 signaling.

Our additional research and preclinical programs

exoVACC: a modular platform for constructing precision vaccines

We believe that our engEx Platform is well-suited to create vaccines that could elicit a potent comprehensive immune response, including antibody and CD8 T cell immunity. We refer to this capability as our exoVACC Precision Engineered Vaccine Technology Platform, or our exoVACC Platform. Our exoVACC Platform is designed to allow us to engineer vaccines to provide simultaneous delivery of antigen(s) and adjuvant to the same APC, with flexibility to display multiple antigens either on the surface or inside the lumen of the exosome. In addition to our ability to use our exoVACC Platform to engineer cells to produce our antigen displaying vaccine candidates, we have developed methods for chemical conjugation of vaccine antigen candidates for rapid screening and potential therapeutic use. We can shape the immune-response by the choice of adjuvant molecules, which typically activate the innate immune-response, including our STING agonist used in exoSTING, toll-like receptor, or TLR, agonists or other adjuvants to tailor the desired immune response. We intend to utilize our exoVACC Platform to develop vaccine candidates that may be useful in infectious disease and cancer settings where the antigens are known.

exoVACC Precision Engineered Vaccine Technology Platform

The figure above describes our exoVACC Platform. By combining our engEx Platform with exogenous loading methods, we have developed a modular platform that allows us to generate custom exosomes for particular vaccine purposes. We have successfully generated exosomes with surface or luminal antigens, expressing targeting ligands against particular antigen presenting cell populations (e.g., anti-Clec9a to target cDC1 cells), expressing co-stimulatory molecules, and have loaded various adjuvants.

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We have partnered with The Ragon Institute of MGH, MIT and Harvard to develop vaccines to protect against HIV and SARS-CoV-2 by eliciting a protective immune response. Both HIV and SARS-CoV2 mutate at a very high rate, therefore identifying invariant residues that are structurally constrained is an essential aspect for antigen selection. Our collaborator, Bruce Walker’s laboratory at Ragon Institute has developed a proprietary algorithm to predict T cell epitopes for HIV that are postulated to generate protective immune-responses for the vast majority of patients. A similar approach is used to identify regions of SARS-CoV2 proteome that are structurally constrained and invariant across all the known SARS-CoV2 variants of concern (VOC) but also conserved across the family of beta coronaviruses and the Walker lab has provided those antigen sequences to us under our agreement to construct potential exoVACC candidates. This approach provides a unique opportunity to develop a pan-beta coronavirus vaccine that could protect not only against the current variants but also from future zoonotic transmission of beta-coronaviruses from bats that could happen in the future.

We have developed an exosome-based pan beta-coronavirus vaccine (exoVACC PBCV) that is designed to induce both humoral responses against the SARS CoV-2 and SARS CoV1 receptor binding domain (RBD), and robust mucosal resident memory CD8 T cell responses against a broad range of betacoronavirus (Beta-CoV) family members. exoVACC PBCV is composed of exosomes stably expressing: 1) the SARS CoV-2 and SARS CoV1 receptor binding domain (RBD) on the exosome surface; 2) luminally expressed CD8 T cell peptide antigens against multiple beta-coronaviruses and; 3) our CDN STING agonist adjuvant that induces robust humoral and cellular immune responses. Our SARS-CoV-2 vaccines studies have been supported by a grant application jointly submitted by the Walker lab and Codiak and awarded by Evergrande Foundation.

Using the PTGFRN scaffold, we have stably expressed approximately 300 copies of the SARS CoV-2 RBD on the exosome surface. Our vaccine candidate in preclinical studies shows the development of a potent neutralizing immune response that can neutralize the current SARS-CoV2 variants (VOC). The pan beta-coronavirus CD8 T cell antigens have been identified using a novel protein structure network analysis and HLA I-peptide binding stability assays to identify mutationally constrained residues that are critical for viral infectivity and replication. These CD8 T cell epitopes are conserved among both circulating VOC and across the beta-coronavirus subfamily and, importantly, elicit antigen-specific T cell reactivity in SARS CoV-2 convalescent individuals but much less in SARS CoV-2 naive subjects who have received a mRNA-based vaccine, suggesting they may provide a protective T cell immune response not currently elicited with the current vaccines. These T-cell epitopes have been engineered as a fusion to PTGFRN in the lumen of the exosome. Preclinical studies with our current vaccine candidate demonstrate the induction of a robust T-cell response directed against these epitopes. In summary, we have demonstrated that exoVACC PBCV elicits broadly neutralizing antibodies capable of binding to major SARS-Cov2 variants of concern and elicit tissue resident CD8 T-cell responses broadly reactive against multiple beta-CoV viruses. Therefore, we believe that a combined T and B cell based vaccination strategy may have the best potential to provide durable protection against a broad and evolving family of xenotropic viruses such as the beta-coronaviruses. We expect to further screen additional exoVACC PBCV candidates and identify the most optimal expression of RBD and T-cell epitope that may provide an optimal immune response to protect from infection with multiple beta-coronaviruses.

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SARS-CoV-2 exoVACC Example

The figure above describes an example of an exoVACC vaccine candidate for SARS-CoV-2. Our exoVACC Platform is used to engineer exosomes that contain both surface B cell epitopes (e.g., receptor binding domain) as well as luminal highly conserved T cell epitopes. The engineered multifunctional exosome is then exogenously loaded with an adjuvant, such as a CDN STING agonist. The combination of both surface B cell epitopes and luminal T cell epitopes is expected to generate both antibody and cytotoxic T cell responses.

The illustration above shows the development of a comprehensive B and T cell mediated immune response following vaccination with our current exoVACC PBCV candidate. Panel A shows our current vaccine construct with SARS-CoV2 RBD fused to the N-terminus of PTGFRN and the conserved T-cell epitopes fused to the C-terminus of PTGFRN. Panel B: Exosome fused RBD (exoRBD) generates significantly higher neutralizing antibody titers as compared to free RBD. Panel C: The serum from mice immunized with exoRBD blocks replication of both WT as well as the Delta variant of SARS-CoV2 virus in a pseudotype virus neutralization assay. Panel C: Demonstrates significantly higher T-cell responses elicited by exoRBD harboring conserved T cell epitopes (exoRBD-T).

We have also established a collaboration with Washington University in St. Louis for access to unique, proprietary tumor neoantigens to evaluate in potential exoVACC candidates. We plan to utilize the same general approach of antigen and adjuvant co-delivery to select APC subpopulations with adjuvants that promote strong Th1 anti-tumor T cell responses.

We plan to pursue additional collaborations to acquire rights to other unique and valuable antigens.

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engEx-AAV and non-viral precision delivery

It has been known for some time that production of various serotypes of AAV is associated with stochastic incorporation of viral particles into exosomes. These AAV particles can be seen in electron micrographs of purified exosomes inside the lumen of the exosome and occur as either single or multiple loaded capsids per exosome. The relative efficiency of stochastic loading is low, with most exosomes lacking viral particles and the majority that contain them having only one to two capsids per exosome. We have used our engEx Platform and BASP1 to develop methods to enhance luminal loading into exosomes and further optimization work is proceeding. Our preliminary studies have shown an up to 50-fold enhancement of AAV luminal loading. These studies demonstrate the feasibility of using our engEx Platform and our engineering technologies to improve the efficiency of AAV luminal loading.

Recombinant adeno-associated virus, or rAAV, has been developed as a successful vector for both basic research and human gene therapy. However, neutralizing antibodies, or NAbs, against AAV capsids can abolish AAV infectivity on target cells, reducing the transduction efficacy. We have addressed the question of whether the application of our engEx Platform to AAV, or engEx-AAV, is subject to inhibition by virus serotype specific neutralizing antibodies in an in vitro assay examining gene transfer. The results suggest that luminal AAV in engEx-AAV is not susceptible to antibody neutralization. These studies also confirm that engEx-AAV efficiently delivers the transgene and that the transgene is expressed in vitro. By correcting for plasmid copy number it appears that engEx-AAV is more efficient than wild-type AAV at transducing cells based upon the greater fluorescence of the cells transduced with a luciferase containing DNA sequence. We have also confirmed gene expression in vivo following rat intra-ocular administration of engEx-AAV. Histological analysis demonstrated robust uptake of exosomes in the retinal ganglion cells with concomitant functional gene transfer.

engEx-AAV Resistant to Antibody Neutralization, Functional in vitro and in vivo,

Can Be Engineered by Our engEx Platform

The figure above describes our engEx-AAV platform. A) Isolation of highly pure exosomes from AAV expressing cells results in some AAV in the exosome fraction (white band), while the majority of free AAV is pelleted at the bottom. EM pictures illustrate the difference between engEx-AAV and free AAV. B) engEx-AAV or free AAV expressing secreted nanoLuciferase were incubated with various concentrations of human IVIG before transduction of HEK 293 cells. While free AAV was neutralized by increasing concentrations of IVIG, engEx-AAV was resistant to neutralization and had increased activity vs free AAV. C) engEx-AAV expressing secreted nanoLuciferase was intravitreally administered to rat eyes and two weeks later, eyes were collected and luciferase levels were measured following tissue homogenization. D) Diagram of how engEx can be used to re-direct exosome tropism as well as increase the amount of AAV loaded into exosomes. E) Using the engEx Platform, HEK 293 cells were engineered to express various configurations of a luminal anti-AAV affinity ligand (engEx-1, 2 or 3). AAV was generated from WT HEK 293 or three engEx variants by triple transfection and exosomes were purified. AAV genome copy numbers were measured by qPCR in the conditioned media and exosome fraction, and data shown here represents the fold improvement of total AAV that is found in exosome fraction from engEx engineered cells versus unmodified HEK293 cells.

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The observations described above suggest several differentiating properties for engEx-AAV. Our engEx-AAV constructs are functional vehicles for non-viral gene transfer that we believe can markedly enhance the level of gene expression as compared to AAV alone. Moreover, packaging the AAV in an exosome using engEx-AAV has shown evidence of “immune cloaking” of the luminal AAV due to the lack of AAV neutralization with immune sera specific for the serotype of the virus capsid. With the coupling of exosome tropism engineering with our engEx Platform, engEx-AAV could facilitate cell selective, non-viral gene delivery to specific cells and cellular compartments. These attributes may allow for:

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Collaborations

Jazz Pharmaceuticals

In January 2019, we entered into a Collaboration and License Agreement with Jazz focused on the research, development and commercialization of exosome therapeutics to treat cancer. Pursuant to the agreement, we granted Jazz an exclusive, worldwide, sublicensable royalty-bearing license to develop, manufacture and commercialize therapeutic candidates directed at up to five oncogene targets to be developed using our engEx Platform for exosome therapeutics. The targets have been validated in hematological malignancies and solid tumors but generally have been undruggable with current modalities. On December 23, 2020, we and Jazz entered into an amendment to the collaboration agreement. The amendment extended the time available for Jazz to nominate a fifth target to July 2, 2021.

Under the terms of the agreement, we are responsible for the initial development of therapeutic candidates directed at all five targets, as well as the costs associated with such development activities. In addition, we are responsible for development costs up to and including IND acceptance, and certain development costs of the Phase 1, Phase 1/2 and Phase 2 clinical trials for each of the first two therapeutic candidates to commence clinical trials. In April 2021, we and Jazz mutually agreed to discontinue work on exoASO™-STAT3, or STAT3, one of the five oncogene targets that were subject to the collaboration agreement. On June 30, 2021, Jazz formally nominated the fifth collaboration target. In January 2022, we and Jazz mutually agreed to discontinue work on the NRAS program. As a result of this discontinuation, Jazz may nominate a replacement target, subject to nomination requirements as outlined in the collaboration agreement.

Following the conclusion of the applicable clinical trials for the first two candidates, and for the remaining three candidates, Jazz will be responsible for the further development and associated costs of the therapeutic candidates, including all Phase 3 and any Phase 4 clinical trials, potential regulatory submissions and commercialization for each product at its sole cost and expense. We have the option to participate in co-commercialization and cost/profit-sharing in the US and Canada on up to two products, subject to a one-time veto right by Jazz, which exercise of such veto may result in an additional $20.0 million milestone payment to us related to regulatory approval of the product. Should we choose to exercise this option, we and Jazz will equally split most of the remaining development costs and the net profits or losses in the US and Canada, while we would receive milestones and royalties for sales in other parts of the world. In the event that we do not exercise our option, we will receive milestones and royalties based upon sales worldwide.

As part of the agreement, Jazz paid us an upfront payment of $56.0 million. We are eligible to receive up to $20.0 million in preclinical development milestone payments, the first of which is for $10.0 million and will be due from Jazz upon the second initiation of IND-enabling toxicology studies for a collaboration target. We are also eligible to receive milestone payments totaling up to $200.0 million per product based on IND acceptance, clinical and regulatory milestones, including approvals in the US, the European Union, or the EU, and Japan, and sales milestones. We are also eligible to receive tiered royalties on net sales of each approved product, with percentages ranging from mid-single digits in the lowest tier to high teens in the highest tier, excluding such net sales in the US and Canada if we have exercised our option to co-commercialize the related product. The milestone and royalty payments are each subject to reduction under certain specified conditions set forth in the agreement, provided, however, that in the case of a termination with respect to a licensed compound that is a development candidate under the agreement, Jazz will maintain its obligation to reimburse us for certain development costs.

Either party can terminate the agreement with respect to a region and a target upon the other party’s material breach relating to such region and target, subject to specified notice and cure provisions. Jazz also has the right to terminate the agreement in its entirety or in part (with respect to a particular collaboration target, research program, licensed compound or product, region or, in some cases, country) for convenience at any time upon 180 days’ written notice or for safety reasons immediately upon notice, provided, however, that in the case of a termination for convenience with respect to a licensed compound that is a development candidate, Jazz will maintain its obligation to reimburse us for certain development costs.

Absent early termination, the term of the agreement will continue on a country-by-country basis and licensed product-by-licensed product basis, until the expiration of the royalty payment obligations for the country and the licensed product (or, in the case of a shared territory for an optioned product, will continue for so long as such optioned product is being sold by Jazz or its affiliates or sublicensees in the shared territory).

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Sarepta Therapeutics

In June 2020, we entered into a two-year Research License and Option Agreement with Sarepta focused on the use of exosomes for non-viral delivery of AAV, gene-editing and RNA therapeutics to address five agreed targets associated with neuromuscular diseases. Pursuant to the agreement, we received funding to conduct collaborative research and Sarepta had options to enter into exclusive, worldwide licenses for each of the agreed targets to develop, commercialize and manufacture therapeutic candidates developed using our engEx Platform for exosome therapeutics. For each target option exercised, we would have been eligible to receive an option exercise fee, milestones, and royalties. Each target was well-understood to be therapeutically relevant to its associated neuromuscular disease.

Under the terms of the agreement, we granted to Sarepta a non-exclusive, royalty-free, worldwide license, with a limited right to sublicense, to use certain of our intellectual property in the conduct of activities for which Sarepta was responsible under the agreement.

Pursuant to the terms of the agreement, we granted to Sarepta an option to obtain an exclusive, worldwide, sublicensable license to use certain of our intellectual property for the development, manufacturing and commercialization of exosome therapeutic candidates directed to one or more of the research targets.

Under the terms of the research agreement, we received up-front and non-refundable cash payments totaling $10.0 million, consisting of a $7.0 million up-front payment and a $3.0 million up-front research services prepayment. In addition, we were eligible for the reimbursement of costs incurred in the execution of the research plan. To the extent Sarepta exercised its option and the parties entered into a definitive license agreement with respect to any target included in the arrangement, Sarepta would have been obligated to remit an option exercise payment of $12.5 million to us per target, up to a total of $62.5 million if all options were exercised. We were eligible to receive up to $192.5 million in development and regulatory milestones per target, plus tiered royalties on the sales of licensed products. One of the selected targets was eligible to generate additional milestone payments on the achievement of certain development and regulatory milestones.

On October 1, 2021, Sarepta notified us that it was terminating early the two-year Research License and Option Agreement, effective June 17, 2020, between Sarepta and us. The termination was effective as of December 3, 2021.

Kayla Therapeutics

In November 2018, we entered into a License Agreement with Kayla, pursuant to which we obtained a co-exclusive worldwide, sublicensable license under certain patent rights and to related know-how and methods to research, develop, manufacture and commercialize exosome compounds and products covered by such patent rights in all diagnostic, prophylactic and therapeutic uses. The foregoing license is co-exclusive with Kayla, but Kayla’s retained rights are subject to certain restrictions.

During the first six years following the effective date of the agreement, Kayla and its affiliates may not research, develop, manufacture or commercialize anywhere in the world any product containing a small molecule STING agonist and an exosome. In addition, during the term of the agreement, Kayla and its affiliates may not grant a license to any third party under the licensed patent rights to, develop, manufacture or commercialize anywhere in the world a product containing certain STING compounds for therapeutic or veterinary purpose. The agreement also restricts us from developing any competing product containing a small molecule STING agonist and an exosome until the expiration of a non-compete period determined by the achievement of clinical milestones.

As of March 1, 2022, the patent portfolio licensed from Kayla consists of three US patents, one European patent, one Chinese patent, and two worldwide pending applications. The patent rights licensed to us under the patent and patent application relate to certain modified cyclic dinucleotides compositions of matter.

We have certain diligence obligations under the license agreement, which include using commercially reasonable efforts to develop, commercialize and market the products developed under the licensed patent rights, including using commercially reasonable efforts to initiate a cohort extension of a Phase 1/2 trial after obtaining IND approval.

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As partial consideration for the license, we paid Kayla an up-front payment of $6.5 million and issued to Kayla 118,212 shares of common stock. Based on the progress we make in the advancement of licensed products, we are required to make aggregate milestone payments of up to $100.0 million in cash payments and up to $13.0 million payable in shares of our common stock upon the achievement of specified clinical and regulatory milestones, including approvals in the US, the EU and Japan. The first eligible milestone, for which we are obligated to make a nonrefundable payment to Kayla of $15.0 million in cash and $5.3 million in common stock, with the price per share in common stock valued as set forth in the license agreement, occurred upon the first dosing of a licensed product (i.e., exoSTING) to the first subject in a Phase 1/2 clinical trial in September 2020. In addition, we are required to pay to Kayla a percentage of the payments that we receive from sublicensees of the rights licensed to us by Kayla, excluding any royalties. This percentage varies from single digits to low double digits.

We are obligated to pay to Kayla tiered royalties ranging from low single-digits to mid single-digits based on annual net sales by us, our affiliates and our sublicensees of licensed products. The royalty term is determined on a product-by-product and country-by-country basis and continues until the later of (i) the expiration of the last valid claim of the licensed patent rights that covers such product in such country, (ii) the loss or expiration of any period of marketing exclusivity for such product in such country, or (iii) ten years after the first commercial sale of such product in such country; provided that if the royalty is payable when no valid claim covers a given product in a given country, the royalty rate for sales of such product in such country is decreased.

Following the first dosing of a licensed product in a pivotal trial and payment of the related milestone, we will have the right to control prosecution of the licensed patents, to the extent such licensed patents (i) are the only patents we own or control that claim the composition of matter of a licensed product and (ii) have not been licensed by Kayla to a third party for the development of products containing certain STING compounds. Additionally, following such milestone, we will have the right to control enforcement of the licensed patents, to the extent such patents are the only patents we own or control that claim the composition of matter of a licensed product, as well as those licensed patents that Kayla has not licensed to a third party for the development of products containing certain STING compounds.

Unless terminated earlier, the term of the license agreement will continue on a country-by-country basis and licensed product-by-licensed product basis, until the expiration of the royalty term for such licensed product. We may terminate the license agreement on a licensed compound-by-licensed compound basis and on a region-by-region basis for any reason upon 30 days prior written notice to Kayla. Either party may terminate the agreement upon the other party’s material breach, subject to specified notice and cure provisions.

Lonza

On November 1, 2021, we and Lonza entered into an Asset Purchase Agreement, or the APA, pursuant to which Lonza acquired our exosome manufacturing facility and related assets, and subleased the premises, located at 4 Hartwell Place, Lexington, Massachusetts. On November 15, 2021, we and Lonza closed the transactions contemplated by the APA, or the Lonza Closing. In connection with the Lonza Closing, and as consideration for the APA, we and Lonza entered into a Manufacturing Services Agreement, or the MSA. Pursuant to the MSA, Lonza will become the exclusive manufacturing partner for future clinical and commercial manufacturing of our exosome products pipeline, subject to limited exceptions. As consideration for the transactions contemplated by the APA and the associated ancillary agreements, we are entitled to approximately $65.0 million worth of exosome manufacturing services for our clinical programs during the next four years. Commencing in 2026, we shall purchase from Lonza a contractually agreed minimum amount of exosome manufacturing services per year for 10 years, or if earlier, until the fifth (5th) anniversary of the first commercial sale of a Codiak exosome product, subject to limited exceptions.

Also in connection with the Lonza Closing, we and Lonza entered into a Licensing and Collaboration Agreement, or the License. Pursuant to the License, we granted Lonza a worldwide, exclusive and sub-licensable license to our high-throughput exosome manufacturing intellectual property in the contract development and manufacturing field, and a worldwide, non-exclusive and sub-licensable license to such intellectual property for non-therapeutical uses outside the contract development and manufacturing field. Pursuant to the License, we are eligible to receive from Lonza a double-digit percentage of future sublicensing revenues. We shall retain its pipeline of therapeutic candidates and core exosome engineering, drug-loading expertise and related intellectual property. The companies will collaborate to establish a joint Center of Excellence for further development of exosome manufacturing technology, with a shared oversight committee. The Center of Excellence will leverage the strengths of both companies to pursue developments in exosome production, purification and analytics.

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Scientific Collaborations

In March 2020, we entered into a Collaboration and Option Agreement with Washington University in St. Louis. We hope to show that a cancer vaccine candidate based on an exoVACC composition can be used to mount an antigen-specific immune-response in various mouse models of sarcoma, and that the exoVACC composition is superior to existing vaccine strategies. Under the agreement, we have an option to obtain an exclusive or non-exclusive royalty-bearing license, subject to Washington University in St. Louis’s obligations regarding licensure that may exist in agreements with the U.S. government or other entity as a result of funding aspects of the project, to Washington University in St. Louis’s intellectual property rights arising under the collaboration. The agreement terminates three years from the effective date unless earlier terminated or otherwise extended by mutual agreement of the parties. Either party may also terminate the agreement upon 30 days’ prior written notice.

In February and May of 2020, we entered into two Sponsored Collaboration Research Agreements with The Ragon Institute of MGH, MIT and Harvard and its investigators Dr. Bruce Walker and Dr. Gaurav Gaiha, who are experts in the mechanism of HIV infection control and who are now also working on research related to SARS-CoV-2. The May 2020 agreement aims to develop an exoVACC vaccine candidate for SARS-CoV-2, for which the Ragon team has identified conserved, structurally constrained T cell epitopes. We hope to show that our exoVACC candidates induce both neutralizing antibodies and antigen-specific T cell responses against SARS-CoV-2. Specifically, the ability to target immune-responses to the lung and other mucosal surfaces where infection occurs could represent an advance in the fight against SARS-CoV-2 and future SARS coronaviruses. The February 2020 agreement aims to develop an exoVACC vaccine candidate for HIV, for which Drs. Walker and Gaiha have identified HIV viral proteins that are recognized by CD8+ T cells in so-called elite controller patients, a rare subset of patients who do not progress to AIDS despite being HIV-positive. The investigators have shown that CD8 T cell recognition of these HIV epitopes may be a strategy to convert non-elite controller HIV patients to elite controller patients. We hope to integrate the HIV antigens identified by Drs. Walker and Gaiha into our exoVACC compositions and test in various mouse models of HIV whether we can generate an immune-response superior to existing HIV vaccine strategies. Under both agreements, we have the option to obtain an exclusive or non-exclusive, royalty-bearing license to Ragon’s intellectual property rights arising under the collaboration. The agreements, which originally were set to terminate one year from their respective effective dates unless earlier terminated or otherwise extended, were extended by mutual consent until February 25, 2023 and May 19, 2023, respectively. Each of the agreements terminates one year from its respective effective date unless earlier terminated or otherwise extended, in each case by mutual written agreement of the parties. We may also terminate each agreement upon 60 days’ prior written notice. Each agreement is also subject to early termination upon an uncured material breach by the other party, or due to our bankruptcy, insolvency or dissolution.

Intellectual property

We believe that the diversity and breadth of our intellectual property is a key asset that provides us with important strategic and competitive advantages. We strive to protect the proprietary inventions, improvements and technology that we expect to be important for our planned commercial activities, including seeking and maintaining domestic and international patent rights whether from our own inventions or licensed from our collaborators or other partners. We also rely on our extensive know-how, trade secrets and other intellectual property that we believe will prove instrumental to our success. Our strategic approach is to seek domestic and international patent protection for new inventions and improvements or, where deemed appropriate, maintain certain inventions and improvements as trade secrets. Our intellectual property estate covers technologies related to our engEx Platform, manufacturing methods, analytical methods, engEx product candidates, pharmaceutical compositions, methods of treating patients, and other core technologies and improvements.

We plan to continue to expand our intellectual property estate by filing provisional and non-provisional patent applications related to our engEx product candidates, engEx Platform advances, manufacturing methods, and other inventions and technologies. Our success will depend, in part, on our ability to obtain and maintain patent and other proprietary protection for commercially important technology, inventions and know-how related to our business, defend and enforce any patents that we may obtain or otherwise control, preserve the confidentiality of our trade secrets, and operate without infringing the valid and enforceable patents and proprietary rights of third parties.

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In addition to filing and prosecuting patent applications in the US, we often file counterpart patent applications in additional countries where we believe such foreign filing is likely to be beneficial, including but not limited to Australia, Brazil, Canada, China, Europe, Hong Kong, India, Israel, Japan, Korea, Mexico, New Zealand and South Africa.

Individual patents extend for varying periods of time, depending upon the date of filing of the patent application, the date of patent issuance and the legal term of patents in the countries in which they are obtained. Generally, patents issued for applications filed in the US are effective for 20 years from the earliest effective filing date for a non-provisional patent application to which priority is claimed. In addition, in certain instances, a patent term can be extended to recapture a portion of the term effectively lost as a result of the FDA regulatory review period. The restoration period cannot be longer than five years and the total patent term, including the restoration period, must not exceed 14 years following FDA approval. The duration of patents outside of the US varies in accordance with provisions of applicable local law, but typically is also 20 years from the earliest effective filing date for a non-provisional patent application to which priority is claimed. However, the actual protection afforded by a patent varies on a product-by-product basis, from country-to-country, and depends upon many factors, including the type of patent, the scope of its coverage, the availability of regulatory-related extensions, the availability of legal remedies in a particular country and the validity and enforceability of the patent.

We believe that we have a strong global intellectual property position, including issued patents and pending patent applications in many key jurisdictions across the globe, as well as broad know-how and trade secrets all directed to our engEx product candidates, engEx Platform technologies, manufacturing and other important technologies. As of March 1, 2022, our patent portfolio consists of approximately 64 patent families, including nine owned issued patents (eight in the US) and approximately four in-licensed issued patents (three in the US); approximately 38 owned or in-licensed pending applications in the US, and approximately 257 owned or in-licensed pending applications in jurisdictions outside of the US (including active PCT applications). Our objective is to continue to expand our portfolio of patents and patent applications in order to protect our engEx Platform, engEx product candidates and manufacturing processes. Examples of the product candidates and technology areas covered by our intellectual property portfolio are described below.

engEx Platform intellectual property

Our intellectual property portfolio includes numerous patents and pending patent applications that relate to innovations that we use to engineer exosomes. Our engEx Platform patent portfolio includes patent filings directed to:

We filed these patent applications in the PCT and/or major commercial markets and other countries of commercial relevance. We expect our patents in these families, if issued, to expire between 2038 and 2041, depending on patent family, excluding any patent term adjustments or extensions. These patents and pending applications are owned by us.

Each of our engEx product candidates leverages components of our engEx Platform technology and the related intellectual property estate.

engEx product candidate intellectual property

We also file patent applications directed to our engEx product candidates. Such patent filings relate to engineered therapeutic exosome compositions and methods of using such compositions to potentially treat or ameliorate various diseases and conditions. The engEx product candidate patent applications described below are owned by us. The patent applications for our lead programs include patent applications directed to:

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These applications are pending in major commercial markets and other countries of commercial relevance. We expect any patents in these families, if issued, to expire between 2038 and 2039, excluding any patent term adjustments or extensions.

We have additional provisional patent applications and unpublished applications that may relate to current and/or future product candidates depending on the scope of any claims that may ultimately issue. These additional candidates are generally directed to exosomes loaded with payloads designed to deliver therapeutic molecules to many cell types and tissues for the treatment of oncology, immune-based diseases, neurological disorders, neuromuscular disorders, vaccination, gene therapy and rare diseases. We expect the patents in these families, if issued, to expire between 2039 and 2042, excluding any patent term adjustments or extensions.

Manufacturing and analytical intellectual property

Another important aspect of our intellectual property estate relates to methods of making, purifying and characterizing exosomes. Our manufacturing and analytical intellectual property is central to potential commercialization of our exosome therapeutics, if approved, and consists of patent applications, know-how and trade secrets. All the manufacturing and analytical intellectual property listed below is owned by us and includes applications directed to:

Our manufacturing and analytical intellectual property, including know-how, patent applications and trade secrets, is important to the potential commercial success of our product candidates. As discussed above, engineering exosomes in a scalable and reproducible way poses significant challenges. Furthermore, the ability to accurately and precisely measure the characteristics and purity of exosomes has also proved to be extremely difficult. We believe that our early and continued investment in manufacturing and analytical capabilities provides us with an important and durable competitive advantage.

We have additional provisional patent applications and unpublished applications that relate to our current and/or future processes for manufacturing and analyzing our exosomes and engEx product candidates. We expect the patents in these families, if issued, to expire between 2037 and 2042, excluding any patent term adjustments or extensions.

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Trade secrets

We may also rely, in some circumstances, on trade secrets to protect our technology and aspects of our engEx Platform. Trade secrets can be difficult to protect. We seek to protect our technology and engEx product candidates, in part, by entering into confidentiality agreements with those who have access to our confidential information, including our employees, contractors, consultants, collaborators and advisors. We also seek to preserve the integrity and confidentiality of our proprietary technology and processes by maintaining physical security of our premises and physical and electronic security of our information technology systems. Although we have confidence in these individuals, organizations and systems, agreements or security measures may be breached and we may not have adequate remedies for any breach. In addition, our trade secrets may otherwise become known or may be independently discovered by our competitors. To the extent that our employees, contractors, consultants, collaborators and advisors use intellectual property owned by others in their work for us, disputes may arise as to the rights in related or resulting know-how and inventions. For a description of this and other comprehensive risks related to our proprietary technology, inventions, improvements and products, see “Risk Factors”.

Trademarks

Our trademarks are important to us and are generally covered by trademark applications with the USPTO and the trademark offices of other countries. Trademark protection varies in accordance with local law, and continues in some countries as long as the trademark is used and in other countries as long as the trademark is registered.

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Competition

The biotechnology and pharmaceutical industries, including in the exosome therapeutics area, are characterized by rapid growth, a dynamic landscape of competitive product candidates and a strong reliance on intellectual property. While we believe that our engEx Platform, exosome engineering and manufacturing capabilities and product candidate pipeline, together with our resources, industry expertise and proprietary know-how, give us a competitive advantage in the field, we face competition from a variety of organizations. Our competitors include larger pharmaceutical companies, specialty biotechnology companies, academic research institutions, governmental agencies, as well as public and private institutions.

There are several companies that are currently developing exosome-based therapeutics for use in a variety of indications, from cancer to rare disease, to regenerative medicine. Broadly, the development of exosome therapeutics can be segregated into two groups: those that use (a) unmodified cell-derived exosomes and (b) engineered and ex vivo modified exosomes.

Unmodified cell-derived exosomes generally rely on the intrinsic therapeutic activity of cargo in exosomes collected from a specific producer cell type. Typically, these producer cells are stem cells or other precursor cells, and the exosomes are generally used in regenerative medicine, immuno-suppression, and central nervous system modulation. The mechanism of action for these exosomes is not well-understood, and may rely on one or more cargo types including miRNAs, mRNAs, and/or surface proteins. Although none of our engEx product candidates rely on unmodified exosomes isolated from producer cells, there is potential competition in the application and uses of our engEx product candidates with those based on unmodified exosomes. Competitors using unmodified cell-derived exosomes include: Aegle Therapeutics Corp., ArunA Biomedical, Inc., or ArunA, Capricor Therapeutics, Inc. and ReNeuron Group plc. In addition, several small-scale clinical studies using unmodified cell-derived exosomes have been initiated, often led by academic investigators, for a variety of indications including cancer, immune diseases, and stroke.

All of our existing and anticipated engEx product candidates use exosomes that are produced from modified cells and/or are loaded ex vivo with various biologically active molecules. We believe this gives our engEx exosomes desired properties such as predictable pharmacology, defined mechanism of action, reproducible activity and a defined analytical profile. We understand that our competitors using engineered and ex vivo modified exosomes plan to use their candidates in numerous therapeutic applications, some of which may directly compete with our engEx product candidates and early programs. Competing therapeutic applications include cancer, metabolic diseases, various rare diseases, central nervous system disorders, neuromuscular disorders, diseases of the immune system and infectious diseases. Competitors using engineered and ex vivo loaded exosomes include ArunA, AstraZeneca plc, or AstraZeneca, Evox Therapeutics Ltd. and PureTech Health plc. We believe that our engEx product candidates will be the first engineered exosomes to enter human clinical trials.

We also face competition outside of the exosome therapeutics field, including from some of the largest pharmaceutical companies and other specialty biotechnology companies. Our three lead engEx product candidates, exoSTING, exoIL-12 and exoASO-STAT6, face competition from numerous companies.

In the STING Agonist Space:

Bristol Myers Squibb Company, or BMS; Merck & Co., Inc., or Merck; Takeda Pharmaceutical Company Limited; Eisai Co., Ltd., or Eisai; Nimbus Therapeutics, Inc.; GlaxoSmithKline plc, or GSK; F-star Therapeutics, Limited, or F-star; Synlogic, Inc., or Synlogic; Mavupharma, Inc. (acquired by AbbVie Inc.) and others.

Merck, BMS, Eisai, GSK, F-star and Synlogic have initiated clinical trials using STING agonists in cancer patients. Additionally, there are several STING agonist programs that have been described in the literature that are owned or being developed by academic institutions that may soon enter clinical trials.

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In the IL-12 Space:

Astellas Pharma Inc.; Celsion Corporation, or Celsion; Cytix, Inc., or Cytix; Dragonfly Therapeutics Inc.; Eli Lilly and Company; MedImmune, LLC (acquired by AstraZeneca), or MedImmune; Immvira Co Ltd.; Inovio Pharmaceuticals, Inc.; Merck; Moderna, Inc., or Moderna; Neumedicines, Inc., or Neumedicines (acquired by Karyopharm Therapeutics); OncoSec Medical Incorporated, or OncoSec; Rubius Therapeutics, Inc.; Repertoire Immune Medicines, Inc.; Ziopharm Oncology, Inc., or Ziopharm; and others.

The IL-12 programs from Ziopharm, OncoSec, Neumedicines, Celsion, Cytix, Merck and MedImmune are currently being used in clinical trials.

We also face competition related to the therapeutic areas and biologically active molecules we plan to engineer onto or into our engEx exosomes. As described above, our engEx Platform is amenable to creating exosomes capable of delivering and/or displaying numerous classes of biologically active molecules. For each of these therapeutic areas and molecule classes we face competition from numerous large pharmaceutical companies and specialty biotechnology companies.

We also face competition outside of the exosome therapeutics field from large pharmaceutical companies and specialty biotechnology companies using synthetic drug delivery systems such as liposomes, lipid nanoparticles and other non-viral delivery approaches, including Alnylam, Arbutus Biopharma, Arcturus Therapeutics, Inc., Intellia, Ipsen Group, Johnson & Johnson, Luye Pharma Group, Moderna and others. These include marketed products and those that are currently in clinical development.

In addition, many of our current or potential competitors, either alone or with their collaboration partners, have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials and marketing approved products than we do. Mergers and acquisitions in the biopharmaceutical industry may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs. Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any products that we may develop. Our competitors also may obtain FDA or other regulatory approval for their products more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we are able to enter the market. The key competitive factors affecting the success of all of our programs are likely to be their efficacy, safety, convenience and availability of reimbursement.

If our current programs are approved for the indications for which we are currently planning clinical trials, they may compete with other products currently under development. Competition with other related products currently under development may include competition for clinical trial sites, patient recruitment and product sales.

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Government Regulation

Government authorities in the US at the federal, state and local level and in other countries regulate, among other things, the research, development, testing, manufacture, quality control, approval, labeling, packaging, storage, record-keeping, promotion, advertising, distribution, post-approval monitoring and reporting, marketing and export and import of drug and biological products, such as our product candidates and any future product candidates. Generally, before a new drug or biologic can be marketed, considerable data demonstrating its quality, safety and efficacy must be obtained, organized into a format specific for each regulatory authority, submitted for review and approved by the regulatory authority.

U.S. biological product development

In the US, the FDA regulates drugs under the Federal Food, Drug and Cosmetic Act, or FDCA, and its implementing regulations and biologics under the FDCA, the Public Health Service Act, or PHSA, and their implementing regulations. Both drugs and biologics also are subject to other federal, state and local statutes and regulations. The process of obtaining regulatory approvals and the subsequent compliance with appropriate federal, state and local statutes and regulations requires the expenditure of substantial time and financial resources. Failure to comply with the applicable U.S. requirements at any time during the product development process, approval process or post-market may subject an applicant to administrative or judicial sanctions. These sanctions could include, among other actions, the FDA’s refusal to approve pending applications, restrictions on the marketing or manufacturing of the product, withdrawal of an approval or license revocation, a clinical hold, untitled or warning letters, product recalls or market withdrawals, product seizures, detentions or import refusals, total or partial suspension of production or distribution, injunctions, fines, refusals of government contracts, restitution, disgorgement and civil or criminal penalties. Any agency or judicial enforcement action could have a material adverse effect on us.

Our product candidates and any future product candidates must be approved by the FDA through a Biologics License Application, or BLA, process before they may be legally marketed in the US. The process generally involves the following:

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The preclinical and clinical testing and approval process requires substantial time, effort and financial resources, and we cannot be certain that any approvals for our product candidates and any future product candidates will be granted on a timely basis, or at all.

Preclinical studies and IND

Preclinical studies include laboratory evaluation of product chemistry and formulation, as well as in vitro and animal studies to assess the potential for adverse events and in some cases to establish a rationale for therapeutic use. The conduct of preclinical studies is subject to federal regulations and requirements, including GLP regulations for safety/toxicology studies. An IND sponsor must submit the results of the preclinical tests, together with manufacturing information, analytical data, any available clinical data or literature and plans for clinical studies, among other things, to the FDA as part of an IND. An IND is a request for authorization from the FDA to administer an investigational product to humans and must become effective before human clinical trials may begin. Some long-term preclinical testing may continue after the IND is submitted. An IND automatically becomes effective 30 days after receipt by the FDA, unless before that time, the FDA raises concerns or questions related to one or more proposed clinical trials and places the trial on clinical hold. In such a case, the IND sponsor and the FDA must resolve any outstanding concerns before the clinical trial can begin. As a result, submission of an IND may not result in the FDA allowing clinical trials to commence.

Clinical trials

The clinical stage of development involves the administration of the investigational product to healthy volunteers or patients under the supervision of qualified investigators, generally physicians not employed by or under the trial sponsor’s control, in accordance with GCP requirements, which include the requirement that all patients, as well as healthy volunteers, provide their informed consent for their participation in any clinical trial. Clinical trials are conducted under protocols detailing, among other things, the objectives of the clinical trial, dosing procedures, subject selection and exclusion criteria and the parameters to be used to monitor subject safety and assess efficacy. Each protocol, and any subsequent amendments to the protocol, must be submitted to the FDA as part of the IND. Furthermore, each clinical trial and its related documentation must be reviewed and approved by an IRB for each institution at which the clinical trial will be conducted to ensure that the risks to individuals participating in the clinical trials are minimized and are reasonable in relation to anticipated benefits. The IRB also approves the informed consent form that must be provided to each clinical trial subject or his or her legal representative and must monitor the clinical trial until completed.

A sponsor who wishes to conduct a clinical trial outside of the US may, but need not, obtain FDA authorization to conduct the clinical trial under an IND. If a foreign clinical trial is not conducted under an IND, the sponsor may nonetheless be able to submit data from the clinical trial to the FDA in support of a BLA. The FDA will accept a well-designed and well-conducted foreign clinical study not conducted under an IND if the study was conducted in accordance with GCP requirements and the FDA is able to validate the data through an onsite inspection if deemed necessary.

Clinical trials generally are conducted in three sequential phases, known as Phase 1, Phase 2 and Phase 3, and may overlap.

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Post-approval trials, sometimes referred to as Phase 4 clinical trials, may be conducted after initial marketing approval. These trials are used to gain additional experience from the treatment of patients in the intended therapeutic indication. In certain instances, the FDA may mandate the performance of Phase 4 clinical trials as a condition of approval of a BLA. Failure to exhibit due diligence with regard to conducting mandatory Phase 4 clinical trials could result in withdrawal of approval for products.

Progress reports detailing the results of the clinical trials, among other information, must be submitted at least annually to the FDA and written IND safety reports must be submitted to the FDA and the investigators for serious and unexpected suspected adverse events. Findings from other studies or animal or in vitro testing that suggest a significant risk for human subjects and any clinically important increase in the rate of a serious suspected adverse reaction over that listed in the protocol or investigator brochure also must be submitted to the FDA and the investigators. The sponsor must submit an IND safety report within 15 calendar days after the sponsor determines that the information qualifies for reporting. The sponsor also must notify the FDA of any unexpected fatal or life-threatening suspected adverse reaction within seven calendar days after the sponsor’s initial receipt of the information.

Sponsors of clinical trials of certain FDA-regulated products, including prescription drugs and biologics, are required to register and disclose certain clinical trial information on a public registry maintained by the U.S. National Institutes of Health, or NIH. Information related to the product, patient population, phase of investigation, clinical trial sites and investigator, and other aspects of the clinical trial is made public as part of the registration of the clinical trial. Although sponsors are also obligated to disclose the results of their clinical trials after completion, disclosure of the results may be delayed in some cases for up to two years after the date of completion of the trial. Competitors may use this publicly available information to gain knowledge regarding the design and progress of our development programs. Failure to timely register a covered clinical study or to submit study results as provided for in the law can give rise to civil monetary penalties and also prevent the non-compliant party from receiving future grant funds from the federal government. The NIH’s Final Rule on ClinicalTrials.gov registration and reporting requirements became effective in 2017, and both NIH and FDA have signaled the government’s willingness to begin enforcing those requirements against non-compliant clinical trial sponsors. Similar requirements for posting clinical trial information in clinical trial registries exist in other countries outside the US.

Phase 1, Phase 2 and Phase 3 clinical trials may not be completed successfully within any specified period, if at all. The FDA or the sponsor may suspend or terminate a clinical trial at any time on various grounds, including a finding that the patients are being exposed to an unacceptable health risk. Similarly, an IRB can suspend or terminate approval of a clinical trial at its institution if the clinical trial is not being conducted in accordance with the IRB’s requirements or if the biologic has been associated with unexpected serious harm to patients. Additionally, some clinical trials are overseen by an independent group of qualified experts organized by the clinical trial sponsor, known as a data safety monitoring board or committee. This group provides authorization for whether a trial may move forward at designated check points based on access to certain data from the trial. Concurrent with clinical trials, companies usually complete additional animal studies and also must develop additional information about the chemistry and physical characteristics of the biologic as well as finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product and, among other things, companies must develop methods for testing the identity, strength, quality and purity of the final product. Additionally, appropriate packaging must be selected and tested and stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life.

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FDA review and approval process

Following completion of the clinical trials, data are analyzed to assess whether the investigational product is safe and effective for the proposed indicated use or uses. The results of preclinical studies and clinical trials are then submitted to the FDA as part of a BLA, along with proposed labeling, chemistry and manufacturing information to ensure product quality and other relevant data. The BLA is a request for approval to market the biologic for one or more specified indications and must contain proof of safety, purity and potency. The application may include both negative and ambiguous results of preclinical studies and clinical trials, as well as positive findings. Data may come from company-sponsored clinical trials intended to test the safety and efficacy of a product’s use or from a number of alternative sources, including studies initiated by investigators. To support marketing approval, the data submitted must be sufficient in quality and quantity to establish the safety, purity and potency of the investigational product to the satisfaction of the FDA. FDA approval of a BLA must be obtained before a biologic may be marketed in the US.

Under PDUFA, each BLA must be accompanied by a significant user fee, which for federal fiscal year 2021 is $2,875,842 for an application requiring clinical data. The sponsor of an approved BLA is also subject to an annual program fee, which for fiscal year 2021 is $336,432. The FDA adjusts the PDUFA user fees on an annual basis. Fee waivers or reductions are available in certain circumstances, including a waiver of the application fee for the first application filed by a small business. Additionally, no user fees are assessed on BLAs for products designated as orphan drugs, unless the product also includes a non-orphan indication.

The FDA reviews all submitted BLAs before it accepts them for filing and may request additional information rather than accepting the BLA for filing. The FDA must make a decision on accepting a BLA for filing within 60 days of receipt and such decision could include a refusal to file by the FDA. Once the submission is accepted for filing, the FDA begins an in-depth review of the BLA. Under the goals and policies agreed to by the FDA under PDUFA, the FDA has ten months, from the filing date, in which to complete its initial review of an original BLA and respond to the applicant and six months from the filing date of an original BLA designated for priority review. The FDA does not always meet its PDUFA goal dates for standard and priority BLAs and the review process is often extended by FDA requests for additional information or clarification.

Before approving a BLA, the FDA will conduct a pre-approval inspection of the manufacturing facilities for the new product to determine whether they comply with cGMP requirements. The FDA will not approve the product unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. The FDA also may audit data from clinical trials to ensure compliance with GCP requirements. Additionally, the FDA may refer applications for novel products or products which present difficult questions of safety or efficacy to an advisory committee, typically a panel that includes clinicians and other experts, for review, evaluation and a recommendation as to whether the application should be approved and under what conditions, if any. The FDA is not bound by recommendations of an advisory committee, but it considers such recommendations when making decisions on approval. The FDA likely will reanalyze the clinical trial data, which could result in extensive discussions between the FDA and the applicant during the review process.

After the FDA evaluates a BLA, it will issue an approval letter or a Complete Response Letter. An approval letter authorizes commercial marketing of the biologic with specific prescribing information for specific indications. A Complete Response Letter indicates that the review cycle of the application is complete and the application will not be approved in its present form. A Complete Response Letter usually describes all of the specific deficiencies in the BLA identified by the FDA. The Complete Response Letter may require additional clinical data and/or other significant and time-consuming requirements related to clinical trials, preclinical studies or manufacturing. If a Complete Response Letter is issued, the applicant may either resubmit the BLA, addressing all of the deficiencies identified in the letter, or withdraw the application. Even if such data and information are submitted, the FDA may decide that the BLA does not satisfy the criteria for approval. Data obtained from clinical trials are not always conclusive and the FDA may interpret data differently than we interpret the same data.

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If the FDA approves a new product, it may limit the approved indications for use of the product. It may also require that contraindications, warnings or precautions be included in the product labeling. In addition, the FDA may require post-approval studies, including Phase 4 clinical trials, to further assess the product’s safety or efficacy after approval. The agency may also require testing and surveillance programs to monitor the product after commercialization, or impose other conditions, including distribution restrictions or other risk management mechanisms to help ensure that the benefits of the product outweigh the potential risks. Following approval, many types of changes to the approved product, such as adding new indications, manufacturing changes and additional labeling claims, are subject to further testing requirements and FDA review and approval.

Orphan drug designation and exclusivity

Under the Orphan Drug Act, the FDA may grant orphan designation to a drug or biological product intended to treat a rare disease or condition, which is generally a disease or condition that affects fewer than 200,000 individuals in the US, or more than 200,000 individuals in the US and for which there is no reasonable expectation that the cost of developing and making the product available in the US for this type of disease or condition will be recovered from sales of the product.

Orphan drug designation for a biologic must be requested before submitting a BLA. After the FDA grants orphan drug designation, the identity of the therapeutic agent and its potential orphan use are disclosed publicly by the FDA. Orphan drug designation does not convey any advantage in or shorten the duration of the regulatory review and approval process.

If a product that has orphan designation subsequently receives the first FDA approval for the disease or condition for which it has such designation, the product is entitled to orphan product exclusivity, which means that the FDA may not approve any other applications to market the same drug or biologic for the same indication for seven years from the date of such approval, except in limited circumstances, such as a showing of clinical superiority to the product with orphan exclusivity by means of greater effectiveness, greater safety or providing a major contribution to patient care, or in instances of drug supply issues. Competitors, however, may receive approval of either a different product for the same indication or the same product for a different indication but that could be used off-label in the orphan indication. Orphan product exclusivity also could block the approval of one of our products for seven years if a competitor obtains approval before we do for the same product, as defined by the FDA, for the same indication we are seeking approval, or if our product is determined to be contained within the scope of the competitor’s product for the same indication or disease. If one of our products designated as an orphan drug receives marketing approval for an indication broader than that which is designated, it may not be entitled to orphan product exclusivity. Orphan drug status in the EU has similar, but not identical, requirements and benefits.

Expedited development and review programs and accelerated approval

The FDA has a fast track program that is intended to expedite or facilitate the process for reviewing new drugs and biologics that meet certain criteria. Specifically, new drugs and biologics are eligible for fast track designation if they are intended to treat a serious or life-threatening condition and preclinical or clinical data demonstrate the potential to address unmet medical needs for the condition. Fast track designation applies to both the product and the specific indication for which it is being studied. The sponsor of a biologic can request the FDA to designate the product for fast track status any time before receiving BLA approval, but ideally no later than the pre-BLA meeting. In addition, a product is eligible for priority review if the product treats a serious or life-threatening condition and, if approved, would provide a significant improvement in safety and effectiveness compared to available therapies. When a marketing application is submitted with a request for priority review, the FDA determines on a case-by-case basis whether the product candidate represents a significant improvement in treatment, prevention or diagnosis of disease when compared with other available therapies. Significant improvement may be illustrated by evidence of increased effectiveness in the treatment of a condition, elimination or substantial reduction of a treatment-limiting drug reaction, documented enhancement of patient compliance that may lead to improvement in serious outcomes, or evidence of safety and effectiveness in a new subpopulation. The FDA will attempt to direct additional resources to the evaluation of an application for a new drug or biologic designated for priority review in an effort to facilitate the review and, as noted above, the goal date for agency action on a BLA designated for priority review will be reduced from ten months to six months.

A product may also be eligible for accelerated approval if it treats a serious or life-threatening condition and generally provides a meaningful advantage over available therapies. In addition, it must demonstrate an effect on

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a surrogate endpoint that is reasonably likely to predict clinical benefit or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, or IMM, that is reasonably likely to predict an effect on IMM or other clinical benefit. As a condition of approval, the FDA may require that a sponsor of a drug or biologic receiving accelerated approval perform adequate and well-controlled post-marketing clinical trials. If the FDA concludes that a drug or biologic shown to be effective can be safely used only if distribution or use is restricted, it will require such post-marketing restrictions as it deems necessary to assure safe use of the product. Failure to conduct required post-approval studies, or to confirm the predicted clinical benefit of the product during the post-marketing studies, would allow the FDA to withdraw approval of the drug or biologic. In addition, unless otherwise informed by the FDA, the FDA currently requires, as a condition of accelerated approval, that all advertising and promotional materials for the product that are intended for dissemination or publication be submitted to the agency in advance for review.

Additionally, a drug or biologic may be eligible for designation as a breakthrough therapy if the product is intended, alone or in combination with one or more other drugs or biologics, to treat a serious or life-threatening condition and preliminary clinical evidence indicates that the product may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints. The benefits of breakthrough therapy designation include the same benefits as fast track designation, plus intensive guidance from the FDA to ensure an efficient drug development program.

Fast track designation, priority review, accelerated approval and breakthrough therapy designation do not change the standards for approval, but may expedite the development or approval process.

Pediatric information

Under the Pediatric Research Equity Act, or PREA, an original BLA and certain supplements to a BLA must contain data to assess the safety and efficacy of the biologic for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective. The FDA may grant deferrals for submission of a required pediatric assessment or full or partial waivers. A sponsor who is planning to submit a marketing application for a biologic that includes a new active ingredient, new indication, new dosage form, new dosing regimen or new route of administration must submit an initial Pediatric Study Plan, or PSP, within 60 days of an end-of-Phase 2 meeting or, if there is no such meeting, as early as practicable before the initiation of the Phase 3 or Phase 2/3 study. The initial PSP must include an outline of the pediatric study or studies that the sponsor plans to conduct, including study objectives and design, age groups, relevant endpoints and statistical approach, or a justification for not including such detailed information, and any request for a deferral of pediatric assessments or a full or partial waiver of the requirement to provide data from pediatric studies along with supporting information. The FDA and the sponsor must reach an agreement on the PSP. A sponsor can submit amendments to an agreed-upon initial PSP at any time if changes to the pediatric plan need to be considered based on data collected from preclinical studies, early phase clinical trials and/or other clinical development programs.

Either the sponsor or the FDA may request a deferral of pediatric trials for some or all of the pediatric subpopulations. A deferral may be granted for several reasons, including a finding that the product candidate is ready for approval for use in adults before pediatric trials are complete or that additional safety or effectiveness data needs to be collected before the pediatric trials begin. The law now requires the FDA to send a PREA Non-Compliance letter to sponsors who have failed to submit their pediatric assessments required under PREA, have failed to seek or obtain a deferral or deferral extension, or have failed to request approval for a required pediatric formulation. It further requires the FDA to publicly post the PREA Non-Compliance letter and sponsor’s response. Unless otherwise required by regulation, the pediatric data requirements do not apply to products with orphan designation, although FDA has recently taken steps to limit what it considers abuse of this statutory exemption in PREA by announcing that it does not intend to grant any additional orphan drug designations for rare pediatric subpopulations of what is otherwise a common disease.

Post-marketing requirements

Following approval of a new product, the sponsor and the approved product are subject to continuing regulation by the FDA, including, among other things, monitoring and record-keeping activities, reporting of adverse experiences, complying with promotion and advertising requirements, which include restrictions on promoting products for unapproved uses or patient populations (known as ‘‘off-label use’’) and limitations on

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industry-sponsored scientific and educational activities. Although physicians may prescribe legally available products for off-label uses, manufacturers may not market or promote such uses. Prescription drug and biologic promotional materials must be submitted to the FDA in conjunction with their first use. Further, if there are any modifications to the biologic, including changes in indications, labeling or manufacturing processes or facilities, the applicant may be required to submit and obtain FDA approval of a new BLA or BLA supplement, which may require the development of additional data or preclinical studies and clinical trials.

The FDA may also place other conditions on approval, including the requirement for a Risk Evaluation and Mitigation Strategy, or REMS, to assure the safe use of the product. If the FDA concludes a REMS is needed, the sponsor of the BLA must submit a proposed REMS. The FDA will not approve the BLA without an approved REMS, if required. A REMS could include medication guides, physician communication plans or elements to assure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. Any of these limitations on approval or marketing could restrict the commercial promotion, distribution, prescription or dispensing of products.

After a BLA is approved, the biologic also may be subject to official lot release. As part of the manufacturing process, the manufacturer is required to perform certain tests on each lot of the product before it is released for distribution. If the product is subject to official release by the FDA, the manufacturer submits samples of each lot of product to the FDA together with a release protocol showing a summary of the history of manufacture of the lot and the results of all of the manufacturer’s tests performed on the lot. The FDA also may perform certain confirmatory tests on lots of certain biological products before releasing the lots for distribution by the manufacturer. In addition, the FDA may conduct laboratory research related to the regulatory standards on the safety, purity, potency, and effectiveness of biological products. Systems need to be put in place by the product sponsor to record and evaluate adverse events reported by health care providers and patients and to assess product complaints. An increase in severity or new adverse events can result in labeling changes or product recall. Defects in manufacturing of commercial products can result in product recalls.

FDA regulations require that products be manufactured in specific approved facilities and in accordance with cGMP regulations. We rely, and expect to continue to rely, on third parties for the production of clinical and commercial quantities of our products in accordance with cGMP regulations. These manufacturers must comply with cGMP regulations that require, among other things, quality control and quality assurance, the maintenance of records and documentation and the obligation to investigate and correct any deviations from cGMP. Manufacturers and other entities involved in the manufacture and distribution of approved drugs or biologics are required to register their establishments with the FDA and certain state agencies and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with cGMP requirements and other laws. Accordingly, manufacturers must continue to expend time, money and effort in the area of production and quality control to maintain cGMP compliance. The discovery of violative conditions, including failure to conform to cGMP regulations, could result in enforcement actions being taken against the manufacturing facility, the product, and/ or the holder of the approved BLA, including withdrawal of the product from the market. In addition, changes to the manufacturing process or facility generally require prior FDA approval before being implemented.

The FDA may withdraw the approval of a BLA if compliance with regulatory requirements and standards is not maintained or if problems occur after the product reaches the market. Discovery of previously unknown problems, including adverse events of unanticipated severity or frequency, or the failure to comply with the applicable regulatory requirements may result in mandatory revisions to the approved labeling to add new safety information, imposition of post-market or clinical trials to assess new safety risks, or imposition of distribution or other restrictions under a REMS. Other potential consequences include, among other things, restrictions on the marketing or manufacturing of the product, FDA refusal to approve pending applications or supplements to approved BLAs, withdrawal of an approval or license revocation, clinical holds, warning or untitled letters, product recalls, product seizures, refusal to permit the import or export of products, total or partial suspension of production or distribution, injunctions, fines, refusals of government contracts, mandated corrective advertising or communications with doctors, debarment, restitution, disgorgement of profits, consent decrees, corporate integrity agreements, debarment, exclusion from federal health care programs, or civil or criminal penalties. Any agency or judicial enforcement action could have a material adverse effect on our business, reputation, and results of operations.

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US patent term restoration and biologic product marketing exclusivity

Depending upon the timing, duration and specifics of FDA approval of our product candidates and any future product candidates, some of our U.S. patents may be eligible for limited patent term extension under the Drug Price Competition and Patent Term Restoration Act of 1984, commonly referred to as the Hatch Waxman Amendments. The Hatch Waxman Amendments permit restoration of the patent term of up to five years as compensation for patent term lost during product development and the FDA regulatory review process. Patent term restoration, however, cannot extend the remaining term of a patent beyond a total of 14 years from the product’s approval date. The patent term restoration period is generally one half the time between the effective date of an IND and the submission date of a BLA plus the time between the submission date of a BLA and the approval of that application, except that the review period is reduced by any time during which the applicant failed to exercise due diligence. Only one patent applicable to an approved biologic is eligible for the extension and the application for the extension must be submitted prior to the expiration of the patent.

The USPTO, in consultation with the FDA, reviews and approves the application for any patent term extension or restoration. In the future, we may apply for restoration of patent term for our currently owned or licensed patents to add patent life beyond its current expiration date, depending on the expected length of the clinical trials and other factors involved in the filing of the relevant BLA.

The Biologics Price Competition and Innovation Act of 2009, or BPCI Act, amended the PHSA to authorize the FDA to approve similar versions of innovative biologics such as ours, which are also known as “reference biological products.” The pathway authorized under the BPCI Act allows FDA to approve, under an abbreviated application, a biological product that is demonstrated to be “biosimilar” or “interchangeable” with a reference biological product licensed by FDA via a full BLA. Biosimilarity to an approved reference product requires that there be no differences in conditions of use, route of administration, dosage form, and strength, and no clinically meaningful differences between the follow-on biological product and the reference product in terms of safety, purity, and potency. In order to meet the higher hurdle of interchangeability, a sponsor must demonstrate that the biosimilar product can be expected to produce the same clinical result as the reference product, and for a product that is administered more than once, that the risk of switching between the reference product and biosimilar product is not greater than the risk of maintaining the patient on the reference product.

A reference biological product is granted 12 years of data exclusivity from the time of first licensure of the product, which means that the FDA is barred from approving biosimilar applications for 12 years after the reference biological product receives initial marketing approval. The FDA also cannot accept an application for a biosimilar or interchangeable product based on the reference biological product until four years after the date of first licensure of the reference product. “First licensure” typically means the initial date the particular product at issue was licensed in the US. Date of first licensure does not include the date of licensure of (and a new period of exclusivity is not available for) a biological product if the licensure is for a supplement for the biological product or for a subsequent application by the same sponsor or manufacturer of the biological product (or licensor, predecessor in interest, or other related entity) for a change (not including a modification to the structure of the biological product) that results in a new indication, route of administration, dosing schedule, dosage form, delivery system, delivery device or strength, or for a modification to the structure of the biological product that does not result in a change in safety, purity, or potency. Therefore, one must determine whether a new product includes a modification to the structure of a previously licensed product that results in a change in safety, purity or potency to assess whether the licensure of the new product is a first licensure that triggers its own period of exclusivity. Whether a subsequent application, if approved, warrants exclusivity as the “first licensure” of a biological product is determined on a case-by-case basis with data submitted by the sponsor.

The BPCI Act is complex and only beginning to be interpreted and implemented by the FDA. In addition, recent government proposals have sought to reduce the 12-year reference product exclusivity period. Other aspects of the BPCI Act, some of which may impact the exclusivity provisions, have also been the subject of recent litigation and legislative amendments. As a result, the ultimate impact, implementation and meaning of the BPCI Act with respect to product candidates such as ours is subject to significant uncertainty.

Pediatric exclusivity is another type of regulatory market exclusivity in the US. Pediatric exclusivity, if granted, adds six months to existing regulatory exclusivity periods such as orphan product and 12-year reference biological product exclusivity under the BPCI Act. This six-month exclusivity may be granted based on the voluntary completion of a pediatric trial in accordance with an FDA-issued ‘‘Written Request’’ for such a trial. The data do not need to show the product to be effective in the pediatric population studied; rather, the additional

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protection is granted if the pediatric clinical trial is deemed to have fairly responded to the FDA’s Written Request. Although the FDA may issue a Written Request for studies on either approved or unapproved indications, it may only do so where it determines that information relating to that use of a product candidate in a pediatric population, or part of the pediatric population, may produce health benefits in that population. This is not a patent term extension, but it effectively extends the regulatory period during which the FDA cannot approve another application.

US coverage, pricing and reimbursement

Successful commercialization of pharmaceutical products after FDA approval depends on the availability of adequate coverage and reimbursement from third-party payors. Patients who are provided medical treatment for their conditions generally rely on third-party payors to reimburse all or part of the costs associated with their treatment. Adequate coverage and reimbursement from U.S. governmental healthcare programs, such as Medicare and Medicaid, and commercial payors, such as private health insurers and health maintenance organizations, are critical to new product acceptance.

Government authorities and other third-party payors decide which products and treatments they will cover and the amount of reimbursement. Coverage and reimbursement by a third-party payor may depend upon a number of factors, including the third-party payor’s determination that use of a product is:

In the US, no uniform policy of coverage and reimbursement for pharmaceutical products exists among third-party payors. As a result, obtaining coverage and reimbursement approval of a product from a government or other third-party payor is a time consuming and costly process that could require a manufacturer to provide to each payor supporting scientific, clinical and cost effectiveness data for the use of the product on a payor-by-payor basis, with no assurance that coverage and adequate reimbursement from third-party payors will be obtained. There is significant uncertainty related to the insurance coverage and reimbursement of newly approved products. In the US, the principal decisions about reimbursement for new products are typically made by the Centers for Medicare & Medicaid Services, or CMS, an agency within the U.S. Department of Health and Human Services, or HHS, as CMS decides whether and to what extent a new product will be covered and reimbursed under Medicare. Private payors tend to follow CMS to a substantial degree. Even if coverage for a given product is obtained, the resulting reimbursement payment rates might not be adequate to achieve or sustain profitability or may require co-payments that patients find unacceptably high.

Additionally, third-party payors may not cover, or provide adequate reimbursement for, long-term follow-up evaluations required following the use certain pharmaceutical products. Patients are unlikely to use a product unless coverage is provided and reimbursement is adequate to cover a significant portion of the cost of the product. Because novel pharmaceutical products may have a higher cost of goods than conventional therapies, and may require long-term follow-up evaluations, the risk that coverage and reimbursement rates may be inadequate for us to achieve profitability may be greater. There is significant uncertainty related to insurance coverage and reimbursement of newly approved and innovative biological products.

Payment methodologies may be subject to changes in healthcare legislation and regulatory initiatives.

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Moreover, increasing efforts by both federal and state governmental authorities and private third-party payors in the US to cap or reduce healthcare costs may cause such organizations to limit both coverage and the level of reimbursement for newly approved pharmaceutical products and, as a result, they may not cover or provide adequate payment for some products. There has been increasing legislative and enforcement interest in the US with respect to specialty pharmaceutical pricing practices. Manufacturers are experiencing pricing pressures in connection with the sale of pharmaceutical products due to the trend toward managed healthcare, the increasing influence of health maintenance organizations, cost containment initiatives and additional legislative changes.

U.S. healthcare reform

The FDA’s and other regulatory authorities’ policies may change and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of our product candidates. For example, in December 2016, the 21st Century Cures Act, or Cures Act, was signed into law. The Cures Act, among other things, was intended to modernize the regulation of drugs and devices and to spur innovation, but its ultimate implementation is uncertain. Legislative proposals continue to be discussed in the U.S. Congress as potentially leading to a future “Cures 2.0” bill that is expected to have bipartisan support. In addition, in August 2017, the FDA Reauthorization Act was signed into law, which reauthorized the FDA’s user fee programs and included additional drug and biological product provisions. The next legislative reauthorization must be completed in 2022, which has the potential to make further changes to FDA authorities or policies pertaining to biopharmaceutical products. If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may lose any marketing approval that we otherwise may have obtained and we may not achieve or sustain profitability, which would adversely affect our business, prospects, financial condition and results of operations.

In addition, there have been and continue to be a number of legislative initiatives to contain healthcare costs. For example, in March 2010, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act, collectively, the ACA, was passed, which substantially changed the way healthcare is financed by both governmental and private insurers and significantly impacts the U.S. pharmaceutical industry. With regard to biopharmaceutical products, the ACA, among other things, increased the minimum Medicaid rebates owed by manufacturers under the Medicaid Drug Rebate Program and extended the rebate program to individuals enrolled in Medicaid managed care organizations, established annual fees on manufacturers of certain branded prescription drugs, created a new Medicare Part D coverage gap discount program, and expanded the 340B drug discount program. Following several years of litigation in the federal courts, in June 2021 the U.S. Supreme Court upheld the ACA when it dismissed a legal challenge to the ACA’s constitutionality.

As another example, the 2021 Consolidated Appropriations Act signed into law on December 27, 2020 incorporated extensive healthcare provisions and amendments to existing laws, including a requirement that all manufacturers of drugs and biological products covered under Medicare Part B report the product’s average sales price, or ASP, to HHS beginning on January 1, 2022, subject to enforcement via civil money penalties.

In addition, other legislative changes have been proposed and adopted in the US since the ACA was enacted that affect healthcare expenditures. These changes include aggregate reductions to Medicare payments to providers of up to 2% per fiscal year pursuant to the Budget Control Act of 2011, which began in 2013 and will remain in effect through 2030 unless additional Congressional action is taken.

However, due to COVID-19 pandemic relief legislation enacted in 2020 and a further extension legislation signed more recently by President Biden, the 2% Medicare sequester reductions have been suspended from May 1, 2020 through December 31, 2021, and the sequester was extended in order to offset the added expense of the 2020 cancellation.

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Further legislative and regulatory changes under the ACA remain possible, although the administration under President Biden has signaled that it plans to build on the ACA and expand the number of people who are eligible for health insurance subsidies under it. It is unknown what form any such changes or any law would take, and how or whether it may affect the biopharmaceutical industry as a whole or our business in the future. We expect that changes or additions to the ACA, the Medicare and Medicaid programs, changes allowing the federal government to directly negotiate drug prices, and changes stemming from other healthcare reform measures, especially with regard to healthcare access, financing or other legislation in individual states, could have a material adverse effect on the healthcare industry in the US.

Moreover, in July 2021, President Biden issued a sweeping executive order on promoting competition in the American economy that includes several mandates pertaining to the pharmaceutical and healthcare insurance industries. Among other things, the executive order directs FDA to work towards implement a system for importing drugs from Canada (following on a Trump administration notice-and-comment rulemaking on Canadian drug importation that was finalized in October 2020), and to clarify and improve the standards for interchangeable biosimilars. The Biden order also calls on HHS to develop and release a comprehensive plan to combat high prescription drug prices by the end of August 2021, and it includes several directives regarding the Federal Trade Commission’s oversight of potentially anticompetitive practices within the pharmaceutical industry.

While some of these and other proposed measures may require additional authorization to become effective, Congress and the Biden administration have each indicated that it will continue to seek new legislative and/or administrative measures to control drug costs. At the state level, legislatures are increasingly passing legislation and implementing regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures and, in some cases, rules and regulations designed to encourage importation from other countries and bulk purchasing. In December 2020, the U.S. Supreme Court held unanimously that federal law does not preempt the states’ ability to regulate pharmaceutical benefit managers, or PBMs, and other members of the healthcare and pharmaceutical supply chain, an important decision that may lead to further and more aggressive efforts by states in this area.

We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative or executive action. We expect that additional federal and state healthcare reform measures will be adopted in the future, any of which could limit the amounts that federal and state governments will pay for healthcare products and services, which could result in limited coverage and reimbursement and reduced demand for our products, once approved, or additional pricing pressures.

US healthcare laws

Healthcare providers, physicians and third-party payors in the US and elsewhere play a primary role in the recommendation and prescription of pharmaceutical products. Arrangements with third-party payors and customers can expose pharmaceutical manufacturers to broadly applicable fraud and abuse and other healthcare laws and regulations, including, without limitation, the federal Anti-Kickback Statute and the federal False Claims Act, which may constrain the business or financial arrangements and relationships through which such companies conduct research, sell, market and distribute pharmaceutical products. In particular, the promotion, sales and marketing of healthcare items and services, as well as certain business arrangements in the healthcare industry, are subject to extensive laws designed to prevent fraud, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of pricing, discounting, marketing and promotion, structuring and commission(s), certain customer incentive programs and other business arrangements generally. Activities subject to these laws also involve the improper use of information obtained in the course of patient recruitment for clinical trials. The federal and state healthcare laws and regulations that may affect a manufacturer’s ability to operate include, but are not limited to:

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The distribution of pharmaceutical products is subject to additional requirements and regulations, including extensive record-keeping, licensing, storage and security requirements intended to prevent the unauthorized sale of pharmaceutical products.

The scope and enforcement of each of these laws is uncertain and subject to rapid change in the current environment of healthcare reform, especially in light of the lack of applicable precedent and regulations. Efforts to ensure that business arrangements comply with applicable healthcare laws may involve substantial costs. It is possible that governmental and enforcement authorities will conclude that a manufacturer’s business practices may not comply with current or future statutes, regulations or case law interpreting applicable fraud and abuse or other healthcare laws and regulations. If any such actions are instituted against a manufacturer and the manufacturer is not successful in defending itself or asserting its rights, those actions could have a significant impact on the manufacturer’s business, including the imposition of significant civil, criminal and administrative penalties, damages, disgorgement, monetary fines, possible exclusion from participation in Medicare, Medicaid and other federal healthcare programs, as well as additional reporting obligations and oversight if subject to a corporate integrity agreement or other agreement to resolve allegations of non-compliance with these laws, contractual damages, reputational harm, diminished profits and future earnings and curtailment of operations.

European Union drug development

In the EU, our future products may also be subject to extensive regulatory requirements. Following the UK’s departure from the EU on January 31, 2020, the UK followed the same regulations as the EU until the end of 2020, during the so-called Transition Period. As of January 1, 2021, the Medicines and Healthcare products Regulatory Agency (MHRA), is the UK’s standalone medicines and medical devices regulator. As a result of the Northern Ireland protocol, different rules will apply in Northern Ireland than in England, Wales, and Scotland, together, Great Britain (GB); broadly, Northern Ireland will continue to follow the EU regulatory regime, but its national competent authority will remain the MHRA. The MHRA has published detailed guidance for industry and organizations to follow from January 1, 2021 now that the Transition Period is over, which will be updated as the UK’s regulatory position on medicinal products evolves over time. The guidance includes clinical trials, marketing authorizations, importing, exporting, and pharmacovigilance and is relevant to any business involved in the research, development, or commercialization of medicines in the UK or the Transition Period. We are currently evaluating the potential impacts on our business of the Trade and Cooperation Agreement and guidance issued to date by the MHRA regarding the requirements for licensing and marketing medicinal products and drugs in the UK. Since the regulatory framework in the United Kingdom covering the quality, safety and efficacy of pharmaceutical products, clinical trials, marketing authorization, commercial sales and distribution of medicinal products is derived from EU Directives and Regulations, Brexit could materially impact the future regulatory regime that applies to products and the approval of product candidates in the United Kingdom.

Similar to the US, the various phases of preclinical and clinical research in the EU are subject to significant regulatory controls. Although the EU Clinical Trials Directive 2001/20/EC had sought to harmonize the EU clinical trials regulatory framework, setting out common rules for the control and authorization of clinical trials in the EU, the EU member states transposed and applied the provisions of the Directive differently in their national laws. This led to significant variations in the member state regimes.

In April 2014, the EU adopted a new Clinical Trials Regulation (EU) No. 536/2014, which replaces the EU Clinical Trials Directive 2001/20/EC. It overhauls the previous system of approvals for clinical trials in the EU. Specifically, the new legislation, which is directly applicable in all EU member states (meaning that no national implementing legislation in each EU member state is required), aims to harmonize and streamline clinical trial authorization, simplify adverse event reporting procedures, improve the supervision of clinical trials and increase their transparency.

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Before clinical trials may be conducted in any EU Member State, a sponsor must submit a clinical trial authorization application, or CTA, which must be approved in each country in which the sponsor intends to perform a clinical trial. The procedure for submitting a CTA was set forth in the EU Clinical Trial Directive. However, the way clinical trials are conducted in the EU underwent a major change when the Clinical Trial Regulation became effective, which occurred on January 31, 2022. The Regulation harmonizes the assessment and supervision processes for clinical trials throughout the EU, via an EU portal and database. Under the EU Clinical Trials Regulation, a harmonized assessment and supervision processes was implemented as of January 31, 2022 for clinical trials throughout the EU, via a Clinical Trials Information System (“CTIS”). The CTIS will contain the centralized EU portal and database for clinical trials conducted in the EU and will allow for a centralized review process. This harmonized submission process will be mandatory for new CTA submissions as of February 1, 2023. For ongoing clinical trials, if a clinical trial continues for more than three years from the day on which the Clinical Trials Regulation became applicable, the Clinical Trials Regulation will at that time begin to apply to the clinical trial.

European Union drug marketing

Much like the Anti-Kickback Statute prohibition in the US, the provision of benefits or advantages to physicians to induce or encourage the prescription, recommendation, endorsement, purchase, supply, order or use of medicinal products is also prohibited in the EU. The provision of benefits or advantages to physicians is governed by the national anti-bribery laws of EU member states, which in the UK is the Bribery Act 2010. Infringement of these laws could result in substantial fines and imprisonment.

Payments made to physicians in certain EU member states must be publicly disclosed. Moreover, agreements with physicians often must be the subject of prior notification and approval by the physician’s employer, his or her competent professional organization and/or the regulatory authorities of the individual EU member states. These requirements are provided in the national laws, industry codes or professional codes of conduct, applicable in the EU member states. Failure to comply with these requirements could result in reputational risk, public reprimands, administrative penalties, fines or imprisonment.

European Union drug review and approval

In the European Economic Area, or EEA, which comprises the 27 member states of the EU and Iceland, Liechtenstein and Norway, medicinal products can only be commercialized after obtaining a Marketing Authorization, or MA. There are two main routes to obtain a marketing authorization.

The first route is an MA is issued by the European Commission through the Centralized Procedure, based on the opinion of the Committee for Medicinal Products for Human Use, or CHMP, of the EMA, and is valid throughout the entire territory of the EEA. The Centralized Procedure is mandatory for certain types of products, such as biotechnology medicinal products, orphan medicinal products, advanced therapy medicines such as gene therapy, somatic cell therapy or tissue engineered medicines and medicinal products containing a new active substance indicated for the treatment of HIV, AIDS, cancer, neurodegenerative disorders, diabetes, autoimmune and other immune dysfunctions and viral diseases. The Centralized Procedure is optional for products containing a new active substance not yet authorized in the EEA, or for products that constitute a significant therapeutic, scientific or technical innovation or which are in the interest of public health in the EU.

National MAs, which are issued by the competent authorities of the member states of the EEA and only cover their respective territory, are available for products not falling within the mandatory scope of the Centralized Procedure.

Where a product has already been authorized for marketing in a member states of the EEA, this National MA can be recognized in other member states through the Mutual Recognition Procedure, one of the options for the second route to obtain an MA. If the product has not received a National MA in any member state at the time of application, it can be approved simultaneously in various member states through the Decentralized Procedure the other option for the second route to obtain an MA. Under the Decentralized Procedure an identical dossier is submitted to the competent authorities of each of the member states in which the MA is sought, one of which is selected by the applicant as the Reference Member State, or RMS. The competent authority of the RMS prepares a draft assessment report, a draft summary of the product characteristics, or SPC, and a draft of the labeling and package leaflet, which are sent to the other member states (referred to as the Member States Concerned) for their approval. If the Member States Concerned raise no objections, based on a potential serious risk to public

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health, to the assessment, SPC, labeling, or packaging proposed by the RMS, the product is subsequently granted a national MA in all the member states (i.e., in the RMS and the Member States Concerned).

Under the above-described procedures, before granting the MA, the EMA or the competent authorities of the member states of the EEA make an assessment of the risk/benefit balance of the product on the basis of scientific criteria concerning its quality, safety and efficacy.

The EEA also provides opportunities for market exclusivity. Upon receiving marketing authorization in the EEA, innovative medicinal products generally receive eight years of data exclusivity and an additional two years of market exclusivity. If granted, data exclusivity prevents biosimilar applicants from referencing the innovator’s preclinical and clinical trial data contained in the dossier of the reference product when applying for a biosimilar MA during a period of eight years from the date on which the reference product was first authorized in the EEA. During the additional two-year period of market exclusivity, a biosimilar MA can be submitted, and the innovator’s data may be referenced, but no biosimilar product can be marketed until the expiration of the market exclusivity period. The overall ten-year period will be extended to a maximum of eleven years if, during the first eight years of those ten years, the MA holder obtains an authorization for one or more new therapeutic indications which, during the scientific evaluation prior to authorization, is held to bring a significant clinical benefit in comparison with existing therapies. Even if an innovative medicinal product gains the prescribed period of data exclusivity, another company may market another version of the product if such company obtained marketing authorization based on an application with a complete independent data package of pharmaceutical tests, preclinical tests and clinical trials. There is, however, no guarantee that a product will be considered by the EU’s regulatory authorities to be an innovative medicinal product, and products may therefore not qualify for data exclusivity.

European Union orphan designation and exclusivity

In the EU, the EMA’s Committee for Orphan Medicinal Products grants orphan drug designation to promote the development of products that are intended for the diagnosis, prevention or treatment of life threatening or chronically debilitating conditions affecting not more than five in 10,000 persons in the EU (or where it is unlikely that the development of the medicine would generate sufficient return to justify the investment) and for which no satisfactory method of diagnosis, prevention or treatment has been authorized (or, if a method exists, the product would be a significant benefit to those affected).

In the EU, orphan drug designation entitles a party to financial incentives such as reduction of fees or fee waivers and ten years of market exclusivity is granted following medicinal product approval. This period may be reduced to six years if the orphan drug designation criteria are no longer met, including where it is shown that the product is sufficiently profitable not to justify maintenance of market exclusivity. Orphan drug designation must be requested before submitting an application for marketing approval. Orphan drug designation does not convey any advantage in, or shorten the duration of, the regulatory review and approval process.

European data collection

The collection and use of personal health data in the EU is governed by the provisions of the General Data Protection Regulation, or GDPR, and the related national data protection laws of the EU member states. This directive imposes several requirements relating to the consent of the individuals to whom the personal data relates, the information provided to the individuals, notification of data processing obligations to the competent national data protection authorities and the security and confidentiality of the personal data. The GDPR and the related national data protection laws of the EU member states also impose strict rules on the transfer of personal data out of the EU to the US. Failure to comply with the requirements of the GDPR and the related national data protection laws of the EU member states may result in fines and other administrative penalties. The GDPR introduces new data protection requirements in the EU and substantial fines for breaches of the data protection rules. The GDPR regulations may impose additional responsibility and liability in relation to personal data that we process and we may be required to put in place additional mechanisms ensuring compliance with the new data protection rules. This may be onerous and adversely affect our business, financial condition, results of operations and prospects.

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Rest of the world regulation

For other countries outside of the EU and the US, such as countries in Eastern Europe, Latin America or Asia, the requirements governing the conduct of clinical trials, product licensing, pricing and reimbursement vary from country to country. Additionally, the clinical trials must be conducted in accordance with GCP requirements and the applicable regulatory requirements and the ethical principles that have their origin in the Declaration of Helsinki.

If we fail to comply with other regulatory requirements, we may be subject to, among other things, fines, suspension or withdrawal of regulatory approvals, product recalls, seizure of products, operating restrictions and criminal prosecution.

Employees

As of December 31, 2021, we had 102 full-time employees, 66 of our employees have Ph.D., M.D., J.D. or Master degrees and 75 of our employees are engaged in research and development activities. None of our employees are represented by labor unions or covered by collective bargaining agreements. We consider our relationship with our employees to be good.

We operate in a highly competitive environment for human capital, particularly as we seek to attract and retain talent with experience in the biotechnology and pharmaceutical sectors. Our workforce is highly educated, and as of December 31, 2021, 65% of our employees hold Ph.D., M.D., J.D., or Master’s degrees. Among our employees, 50% identify as female and 50% as male. In 2021, we continued our emphasis on diversity, equity and inclusion by expanding our recruiting outreach and conducting internal seminars, trainings, and discussions on inclusive behaviors.

To help promote alignment between our employees and our shareholders, all employees participate in our equity programs through the receipt of new hire and annual equity grants. We believe that in addition to incentivizing growth that leads to shareholder value, broad eligibility for our equity programs helps promote employee retention as these awards generally vest over a four-year period.

Facilities

We lease a facility containing 68,258 square feet of office and laboratory space which is located at 35 CambridgePark Drive, Cambridge, Massachusetts 02140. The lease expires in 2029, subject to one option to extend the lease for ten years. In April 2020, we entered into a sublease with Apic Bio, Inc., or Apic, pursuant to which we subleased to Apic excess capacity in the CambridgePark property. The sublease was set to expire in April 2022, subject to Apic's one option to extend the sublease for 12 months. Effective July 1, 2021, we received notice of the sublessee’s intent to exercise its option to extend the sublease for a one-year period through May 2023.

In addition, we lease a facility containing 18,707 square feet of clinical manufacturing, laboratory and office space, which is located at 4 Hartwell Place, Lexington, Massachusetts 02421. The lease expires in 2029, subject to two options to extend the lease, each for an additional five years. In November 2021, we entered into a sublease agreement for the entirety of its leased space at 4 Hartwell Place. The initial lease term commenced on November 15, 2021 and continues through November 30, 2024. The tenant has the option to extend the sublease term for five 12-month periods on the same terms and conditions as the current sublease, subject to an increase of 2.8% in the annual fixed rent charges.

Legal Proceedings

We are not currently a party to any material legal proceedings.

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Item 1A. Risk Factors.

Investing in our common stock involves a high degree of risk. You should carefully consider the risks described below, together with all other information in this Annual Report on Form 10-K, including our consolidated financial statements and the related notes and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” before deciding whether to invest in our common stock. The occurrence of any of the events or developments described below could harm our business, financial condition, results of operations and growth prospects. In such an event, the market price of our common stock could decline, and you may lose all or part of your investment. Additional risks and uncertainties not presently known to us or that we currently deem immaterial also may impair our business operations.

Risks related to our financial position and need for additional capital

We have incurred net losses in every year since our inception and anticipate that we will continue to incur net losses in the future.

We are a clinical-stage biopharmaceutical company with a limited operating history. Investment in biopharmaceutical product development is highly speculative because it entails substantial upfront capital expenditures and significant risk that any potential product candidate will fail to demonstrate adequate efficacy or an acceptable safety profile, gain regulatory approval and/or become commercially viable. We initiated our clinical trials for our initial engEx product candidates, exoSTING and exoIL-12, in September 2020. We have no products approved for commercial sale and we have not yet demonstrated an ability to successfully conduct or complete clinical trials, to manufacture a commercial-scale product or arrange for a third party to do so on our behalf or conduct sales and marketing activities necessary for successful product commercialization. Engineering exosomes to become potential therapeutics is a novel therapeutic approach and no products based on exosomes have been approved to date in the United States, or the US, or the European Union, or the EU. We have not generated any revenue from product sales to date and we continue to incur significant research and development and other expenses related to our ongoing operations. As a result, we are not profitable and have incurred losses in each period since our inception in 2015. For the years ended December 31, 2021 and 2020 we reported net losses of $37.2 million and $91.7 million, respectively. As of December 31, 2021, we had an accumulated deficit of $325.2 million. We expect to continue to incur significant expenses and operating losses for the foreseeable future and we expect these losses to increase as we continue our research and development, advance certain product candidates into preclinical studies and clinical trials and, if clinical development is successful, seek regulatory approvals for our product candidates. We anticipate that our expenses will increase substantially if, and as, we:

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To become and remain profitable, we or any current or future collaborator must develop and eventually commercialize products with significant market potential at an adequate profit margin after cost of goods sold and other expenses. This will require us to be successful in a range of challenging activities, including completing preclinical studies and clinical trials, obtaining marketing approval for product candidates, manufacturing, marketing and selling products for which we may obtain marketing approval and satisfying any post-marketing requirements. We may never succeed in any or all of these activities and, even if we do, we may never generate revenue that is significant or large enough to achieve profitability. If we do achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis. Our failure to become and remain profitable would decrease the value of our company and could impair our ability to raise capital, maintain our research and development efforts, expand our business or continue our operations. A decline in the value of our company also could cause you to lose all or part of your investment.

Even if we succeed in commercializing one or more of our engEx product candidates, we will continue to incur substantial research and development and other expenditures to develop and market additional product candidates. We may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. The size of our future net losses will depend, in part, on the rate of future growth of our expenses and our ability to generate revenue. Our prior losses and expected future losses have had and will continue to have an adverse effect on our stockholders’ equity and working capital.

We will require additional capital to fund our operations and if we fail to obtain necessary financing, we will not be able to complete the development and commercialization of our product candidates.

Our operations have consumed substantial amounts of cash since inception. We expect to continue to spend substantial amounts to conduct further research and development, preclinical studies and clinical trials of engEx exosomes, enhance the capabilities of our engEx Platform, operate and maintain our own Phase 1/2 clinical manufacturing facility, seek regulatory approvals for our product candidates and launch and commercialize any products for which we receive regulatory approval. As of December 31, 2021, we had $76.9 million of cash and cash equivalents. Based on our current operating plan, we expect that our cash and cash equivalents as of December 31, 2021 will be insufficient to allow us to fund our current operating plan through at least the next twelve months from the filing of our financial statements included in this Annual Report on Form 10-K. However, our future capital requirements and the period for which our existing resources will support our operations may vary significantly from what we expect and we will in any event require additional capital in order to complete clinical development of any of our current engEx product candidates. Our monthly spending levels will vary based on new and ongoing development and corporate activities. Because the length of time and activities associated with development of our engEx Platform, engEx product candidates and development programs is highly uncertain, we are unable to estimate the actual funds we will require for development and any approved marketing and commercialization activities. Our future funding requirements, both near and long-term, will depend on many factors, including, but not limited to:

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We do not have any committed external source of funds or other support for our development and commercialization efforts and we cannot be certain that additional funding will be available on acceptable terms, or at all. Additional proceeds available to us under our Loan and Security Agreement, or the Hercules Loan Agreement, with Hercules Capital, Inc., or Hercules, are conditioned on satisfaction of liquidity and clinical milestones, which may never occur. Until we can generate sufficient product or royalty revenue to finance our cash requirements, which we may never do, we expect to finance our future cash needs through a combination of public or private equity offerings, debt financings, collaborations, strategic alliances, licensing arrangements and other marketing or distribution arrangements. Any additional fundraising efforts may divert our management’s attention from their day-to-day activities, which may adversely affect our ability to develop and commercialize our product candidates. Disruptions in the financial markets in general and more recently due to the COVID-19 pandemic have made equity and debt financing more difficult to obtain and may have a material adverse effect on our ability to meet our fundraising needs. We cannot guarantee that future financing will be available in sufficient amounts or on terms acceptable to us, if at all.

If we raise additional funds through public or private equity offerings, the terms of these securities may include liquidation or other preferences that adversely affect our stockholders’ rights. Further, to the extent that we raise additional capital through the sale of common stock or securities convertible into or exchangeable for common stock, your ownership interest will be diluted. If we raise additional capital through debt financing, we would be subject to fixed payment obligations and may be subject to covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we raise additional capital through marketing and distribution arrangements or other collaborations, strategic alliances or licensing arrangements with third parties, we may have to relinquish certain valuable rights to our product candidates, technologies, future revenue streams or research programs or grant licenses on terms that may not be favorable to us. We also could be required to seek collaborators for one or more of our current or future product candidates at an earlier stage than otherwise would be desirable, or on terms that are less favorable than may otherwise be available, or relinquish or license our rights to product candidates or technologies that we otherwise would seek to develop or commercialize ourselves.

As a result of our recurring losses from operations and recurring negative cash flows from operations, there is uncertainty regarding our ability to maintain liquidity sufficient to operate our business effectively. If we are unable to obtain funding or raise additional capital in sufficient amounts, on terms acceptable to us or on a timely basis, we may have to significantly delay, scale back or discontinue one or more of our research or development programs or be unable to expand our operations or otherwise capitalize on business opportunities, as desired. Any of the above events could significantly harm our business, prospects, financial condition and results of operations and cause the price of our common stock to decline.

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Our independent registered public accounting firm has included an explanatory paragraph relating to our ability to continue as a going concern in its report on our audited financial statements included in this Annual Report on Form 10-K.

The report from our independent registered public accounting firm for the year ended December 31, 2021 includes an explanatory paragraph stating that our losses from operations and required additional funding to finance our operations raise substantial doubt about our ability to continue as a going concern for a period of one year after the date the financial statements are issued. See Note 1 to our consolidated financial statements appearing elsewhere in our Annual Report on Form 10-K for additional information on our assessment.

If we are unable to obtain sufficient funding, our business, prospects, financial condition and results of operations will be materially and adversely affected and we may be unable to continue as a going concern. If we are unable to continue as a going concern, we may have to liquidate our assets and may receive less than the value at which those assets are carried on our audited financial statements, and it is likely that investors will lose all or a part of their investment. If we seek additional financing to fund our business activities in the future and there remains substantial doubt about our ability to continue as a going concern, investors or other financing sources may be unwilling to provide additional funding to us on commercially reasonable terms or at all. There can be no assurance that the current operating plan will be achieved in the time frame anticipated by us, or that our cash resources will fund our operating plan for the period anticipated by the Company or that additional funding will be available on terms acceptable to us, or at all.

We have a limited operating history, which may make it difficult to evaluate our technology and product development capabilities and predict our future performance.

We are a clinical-stage company and initiated clinical trials of our initial engEx product candidates in September 2020. We were formed in 2015, have no products approved for commercial sale and have not generated any revenue from product sales. Our ability to generate product revenue or profits, which we do not expect will occur for many years, if ever, will depend on the successful development and eventual commercialization of our product candidates, which may never occur. We may never be able to develop or commercialize a marketable product.

All of our programs require additional preclinical research and development, clinical development, regulatory approval, obtaining manufacturing supply, capacity and expertise, building of a commercial organization, substantial investment and/or significant marketing efforts before we generate any revenue from product sales. Other programs of ours require additional discovery research and then preclinical development. In addition, our product candidates must be approved for marketing by the FDA or other health regulatory agencies before we may commercialize any product. We have not yet demonstrated an ability to successfully complete any clinical trials, obtain marketing approvals, manufacture a commercial-scale medicine, or arrange for a third party to do so on our behalf or conduct sales and marketing activities necessary for successful commercialization. Consequently, any predictions you make about our future success or viability may not be as accurate as they could be if we had a longer operating history.

Our limited operating history, particularly in light of the nascent exosome therapeutics field, may make it difficult to evaluate our technology and industry and predict our future performance. Though several groups have conducted or are conducting proof of principle studies of therapeutic candidates based on natural exosomes, in most cases, these studies used exosomes secreted from producer cells that were partially purified and administered without further modification. As a result, the relevance of those studies to the evaluation of product candidates developed using our engEx Platform, which generates engineered exosomes, may be difficult to ascertain. Our short history as an operating company and novel therapeutic approach make any assessment of our future success or viability subject to significant uncertainty. We will encounter risks and difficulties frequently experienced by early-stage companies in rapidly evolving fields. If we do not address these risks successfully, our business will suffer. Similarly, we expect that our financial condition and operating results will fluctuate significantly from quarter to quarter and year to year due to a variety of factors, many of which are beyond our control. As a result, our stockholders should not rely upon the results of any quarterly or annual period as an indicator of future operating performance.

In addition, as an early-stage company, we have encountered unforeseen expenses, difficulties, complications, delays and other known and unknown circumstances. As we advance our engEx product

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candidates, we will need to transition from a company with a research focus to a company capable of supporting clinical development and if successful, commercial activities. We may not be successful in such a transition.

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Our existing and any future indebtedness could adversely affect our ability to operate our business.

As of December 31, 2021, we had $25.4 million of outstanding borrowings under the Hercules Loan Agreement. Effective September 17, 2021, we amended the Loan Agreement with Hercules (the Amended Loan Agreement), increasing the aggregate principal amount available from $75.0 million under the Term Loan Facility to $85.0 million, or the Amended Term Loan Facility. Advances under the Amended Term Loan Facility bear interest at a rate equal to the greater of (i) 8.25% plus the Prime Rate (as reported in The Wall Street Journal) less 3.25%, and (ii) 8.25%. The interest only period under the Term Loan Facility was extended from November 1, 2022 to October 1, 2023 under the Amended Term Loan Facility and is further extendable to October 1, 2024 upon achievement of certain clinical milestones. Under the Amended Term Loan Facility, following the interest only period, we will repay the principal balance and interest on the advances in equal monthly installments through October 1, 2025, compared to October 1, 2024 under the Term Loan Facility. Subject to certain conditions set forth in the Amended Loan Agreement, we may borrow up to an additional $50.0 million. Subject to the restrictions in this existing credit facility, we could in the future incur additional indebtedness beyond our borrowings from Hercules.

Our outstanding indebtedness, including any additional indebtedness beyond our borrowings from Hercules, combined with our other financial obligations and contractual commitments could have significant adverse consequences, including:

We intend to satisfy our current and future debt service obligations with our then existing cash and cash equivalents. However, we may not have sufficient funds, and may be unable to arrange for additional financing, to pay the amounts due under the Hercules Loan Agreement or any other debt instruments. Failure to make payments or comply with other covenants under our existing credit facility or such other debt instruments could result in an event of default and acceleration of amounts due. For example, the affirmative covenants under our existing credit facility require us to, among other things, maintain unrestricted cash and cash equivalents in a control account equal to or greater than the lesser of 110% of all outstanding amounts under the credit facility (inclusive of any prepayment charge and end of term charge that would be due and payable if the outstanding loans were prepaid at the time of measurement) plus the amount of our company’s and our subsidiaries’ accounts payable that have not been paid within 90 days from the invoice date and 100% of the cash and cash equivalents of our company and our wholly-owned subsidiary, Codiak Securities Corporation. Under the Hercules Loan Agreement, the occurrence of an event that would reasonably be expected to have a material adverse effect on our business, operations, assets or condition is an event of default. If an event of default occurs and Hercules accelerates the amounts due, we may not be able to make accelerated payments and the lenders could seek to enforce security interests in the collateral securing such indebtedness. In addition, the covenants under our existing credit facility, the pledge of our assets as collateral and the negative pledge with respect to our intellectual property could limit our ability to obtain additional debt financing.

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Our ability to use net operating losses and research and development credits to offset future taxable income may be subject to certain limitations.

As of December 31, 2021, we had U.S. federal and state net operating loss carryforwards of $189.4 million and $188.7 million, respectively, some of which begin to expire in 2035. As of December 31, 2021, we also had U.S. federal and state research and development tax credit carryforwards of $10.5 million and $5.0 million, respectively, which begin to expire in 2035 and 2031, respectively. These net operating loss and tax credit carryforwards could expire unused and be unavailable to offset future taxable income or tax liabilities, respectively. U.S. federal and certain state net operating losses generated in taxable years beginning after December 31, 2017 are not subject to expiration. Federal net operating losses generally may not be carried back to prior taxable years except that, under the Coronavirus Aid, Relief and Economic Security Act, federal net operating losses generated in 2019 and 2020 may be carried back to each of the five taxable years preceding the taxable year in which the loss arises. Additionally, for taxable years beginning after December 31, 2020, the deductibility of federal net operating losses is limited to 80% of our taxable income in such taxable year.

In general, under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, or the Code, and corresponding provisions of state law, a corporation that undergoes an “ownership change” is subject to limitations on its ability to utilize its pre-change net operating loss carryforwards or tax credits, or NOLs or credits, to offset future taxable income. For these purposes, an ownership change generally occurs where the aggregate stock ownership of one or more stockholders or groups of stockholders who owns at least five percent of a corporation’s stock increases its ownership by more than 50 percentage points over its lowest ownership percentage within a specified testing period. Our existing federal and state NOLs and our existing research and development credits may be subject to limitations arising from previous ownership changes and, if we undergo an ownership change, our ability to utilize NOLs or credits could be further limited by Sections 382 and 383 of the Code. In addition, future changes in our stock ownership, many of which are outside of our control, could result in an ownership change under Sections 382 and 383 of the Code. Our NOLs or credits may also be impaired under state law. Accordingly, we may not be able to utilize a material portion of our NOLs or credits. Furthermore, our ability to utilize our NOLs or credits is conditioned upon our attaining profitability and generating U.S. federal and state taxable income. As described above, we have incurred significant net losses since our inception and anticipate that we will continue to incur significant losses for the foreseeable future; and therefore, we do not know whether or when we will generate the U.S. federal or state taxable income necessary to utilize our NOLs or credits that are subject to limitation by Sections 382 and 383 of the Code.

Risks related to our business, technology and industry

We are very early in our development efforts. While we have initiated clinical trials of our initial engEx product candidates, it could be many years before we or our collaborators commercialize a product candidate, if ever. If we are unable to advance our product candidates through clinical development, obtain regulatory approval and ultimately commercialize our product candidates or experience significant delays in doing so, our business will be materially harmed.

We are very early in our development efforts and have focused our research and development efforts to date on enhancing the capabilities of our engEx Platform, advancing our engEx product candidates through preclinical development towards clinical trials, initiating clinical trials for our lead product candidates, exoSTING, exoIL-12 and exoASO-STAT6, working to industrialize engineered exosome manufacturing and identifying our initial targeted cell types, disease indications and preferred routes of administration. Our future success depends heavily on the successful development of our engEx Platform and engEx product candidates. Our ability to generate product revenue, which we do not expect will occur for many years, if ever, will depend heavily on the successful development and eventual commercialization of our product candidates, which may never occur. For example, our research programs may fail to identify potential product candidates for clinical development for a number of reasons. Our research methodology may be unsuccessful in identifying potential product candidates, or our potential product candidates may be shown to have harmful side effects or may have other characteristics that may make the products impractical to manufacture, unmarketable or unlikely to receive marketing approval. We currently generate no revenue from sales of any product and we may never be able to develop or commercialize a marketable product.

We advanced our first three engEx product candidates, exoSTING, exoIL-12 and exoASO-STAT6, into clinical development and expect to advance additional product candidates into clinical development in the future. Commencing clinical trials is subject to clearance by the FDA or other regulatory authorities of our investigational

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new drug applications, or INDs, or other similar applications in foreign countries and finalizing the trial designs based on discussions with the FDA and other regulatory authorities. In the event that the FDA or other regulatory authorities require us to complete additional preclinical studies or we are required to satisfy other requests from the FDA or other regulatory authorities, the commencement of clinical trials may be delayed. Even after we receive and incorporate guidance from these regulatory authorities, the FDA or other regulatory authorities could disagree that we have satisfied their requirements to commence our clinical trials or change their position on the acceptability of our preclinical studies, trial design or the clinical endpoints selected, which may require us to complete additional preclinical studies or clinical trials or impose stricter approval conditions than we currently expect. Prior to commencing any clinical trials, we will also have to obtain approval from the Institutional Review Board, or IRB, or ethics committee for each of the institutions at which we plan to conduct our clinical trials. Moreover, our clinical trial results may show our engEx product candidates to be less effective than expected (e.g., a clinical trial could fail to meet its primary endpoints) or have unacceptable side effects or toxicities.

Our product candidates will require additional preclinical and clinical development, regulatory and marketing approval in multiple jurisdictions, obtaining sufficient manufacturing capacity and expertise for both clinical development and commercial production and substantial investment and significant commercialization efforts before we generate any revenue from product sales. Our product candidates must be approved for marketing by the FDA or certain other regulatory agencies, including the MHRA, before we may commercialize our product candidates.

The success of our current and future engEx product candidates will depend on some or all of the following factors:

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If we do not succeed in one or more of these factors in a timely manner or at all, we could experience significant delays or an inability to successfully commercialize our product candidates, which would materially harm our business. If we do not receive regulatory approvals for our product candidates, we may not be able to continue our operations.

Our business is highly dependent on the success of our initial engEx product candidates, exoSTING, exoIL-12 and exoASO-STAT6, targeting cancer. All of our engEx product candidates and development programs will require significant additional development before we can seek regulatory approval for and launch a product commercially.

Our business and future success is highly dependent on our ability to initiate and complete clinical trials and to obtain regulatory approval of and then successfully launch and commercialize our initial engEx product candidates, exoSTING, exoIL-12 and exoASO-STAT6, and others that may be selected from our development programs.

Our clinical trials may experience complications or delays surrounding trial execution, such as complexities surrounding regulatory acceptance of an IND or CTA, trial design and establishing trial protocols, patient recruitment and enrollment, quality and supply of clinical doses, delays due to the COVID-19 pandemic or safety issues. Any such complications or delays could impact the conduct of our clinical trials and our ability to complete them in a timely manner or at all, which in turn could delay and/or negatively impact the regulatory review and approval of our product candidates.

Our lead product candidates, exoSTING and exoIL-12, are being developed to address solid tumors and we initiated clinical trials for both product candidates in September 2020. exoASO-STAT6 is expected to initiate clinical trials in the first half of 2022. We are highly dependent on the success of these and future clinical trials, the outcomes of which are uncertain. The FDA and other regulatory authorities, such as the MHRA, may disagree with our clinical trial design, may change the requirements for advancement or approval even after it has reviewed and commented on the design of our trials. As a result, the FDA or other regulatory authorities could require us to conduct additional preclinical studies or clinical trials, which could result in delays and significant additional costs, all of which could jeopardize our ability to successfully develop our product candidates.

All of our engEx exosomes are in varying stages of early development and will require additional preclinical and/or clinical development, regulatory review and approval in multiple jurisdictions, substantial investment, access to sufficient commercial manufacturing capacity and significant marketing efforts before we can generate any revenue from product sales. The process for obtaining marketing approval for any product candidate is very long and risky and there will be significant challenges for us to address in order to obtain marketing approval as planned, if at all. In addition, because exoSTING, exoIL-12 and exoASO-STAT6 are our most advanced engEx product candidates, if either exoSTING, exoIL-12 and exoASO-STAT6 encounters safety, efficacy, supply or manufacturing problems, developmental delays, regulatory or commercialization issues or other problems, the value of our engEx Platform could be greatly diminished and our development plans and business would be significantly harmed.

Our engEx product candidates are based on a novel therapeutic approach, which makes it difficult to predict the time and cost of development and of subsequently obtaining regulatory approval, if at all.

Using exosome technology to develop product candidates is a relatively new therapeutic approach and no products based on exosomes have been approved to date in the US, the United Kingdom, or the UK, or the EU. As such it is difficult to accurately predict the developmental challenges we may face for our engEx product candidates as they proceed through development. In addition, because we are just commencing clinical trials with our first engEx product candidates, we have not yet been able to assess safety in humans and there may be short-term or long-term effects from treatment with any product candidates that we develop that we cannot predict at this time. Also, animal models may not exist for some of the diseases we choose to pursue in our programs. As a result of these factors, it is more difficult for us to predict the time and cost of product candidate development

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and we cannot predict whether the application of our engEx Platform, or any similar or competitive exosome technologies, will result in the identification, development and regulatory approval of any products. There can be no assurance that any development problems we experience in the future related to our engEx Platform, exosome therapeutics or any of our research programs will not cause significant delays or unanticipated costs or that such development problems can be solved. Any of these factors may prevent us from completing our preclinical studies or any clinical trials that we may initiate or commercializing any product candidates we may develop on a timely or profitable basis, if at all.

The clinical trial requirements of the FDA, the MHRA and other regulatory authorities and the criteria these regulators use to determine the safety and efficacy of a product candidate vary substantially according to the type, complexity, novelty and intended use and market of the product candidate. No products based on exosomes have been approved to date by regulators. As a result, the regulatory approval process for product candidates such as ours is uncertain, and may be more expensive and take longer than the approval process for product candidates based on other, better known or more extensively studied technologies. It is difficult to determine how long it will take or how much it will cost to obtain regulatory approvals for our product candidates in the US, the UK, the EU or other regions of the world or how long it will take to commercialize our product candidates. Delay or failure to obtain or unexpected costs in obtaining the regulatory approvals necessary to bring a potential product candidate to market could decrease our ability to generate sufficient product revenue and our business, financial condition, results of operations and prospects may be harmed.

Development of new therapeutics involves a lengthy and expensive process, with an uncertain outcome. We may incur additional costs, fail to replicate the positive results from our earlier preclinical or clinical studies or experience delays in completing or ultimately be unable to complete, the development and commercialization of any product candidates.

To obtain the requisite regulatory approvals to commercialize any product candidates, we must demonstrate through extensive preclinical studies and clinical trials that our products are safe and effective in humans. All of our engEx product candidates and exosomes are in early stages of development and thus their risk of failure is high. Before we can commence clinical trials for a product candidate, we must complete extensive preclinical studies that support our filed and planned INDs in the US, or similar applications in other jurisdictions. We cannot be certain of the timely completion or outcome of our preclinical studies and cannot predict if the FDA or other regulatory authorities will accept our proposed clinical programs or if the outcome of our preclinical studies will ultimately support the further development of our product candidates. As a result, we cannot be sure that we will be able to submit INDs or similar applications for our preclinical programs on the timelines we expect, if at all, and we cannot be sure that submission of INDs or similar applications will result in the FDA or other regulatory authorities allowing clinical trials to begin.

Clinical trials are expensive, difficult to design and implement and can take many years to complete and their outcome is inherently uncertain. Failure can occur at any time during, or even after, the clinical trial process and our ongoing and future clinical results may not be successful. We may be unable to establish clinical endpoints that applicable regulatory authorities would consider clinically meaningful and a clinical trial can fail at any stage of testing. The outcome of preclinical studies and early clinical trials may not be predictive of the success of later clinical trials and interim results of a clinical trial do not necessarily predict final results. Differences in trial design between early-stage clinical trials and later-stage clinical trials make it difficult to extrapolate the results of earlier clinical trials to later clinical trials. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their products.

Successful completion of clinical trials is a prerequisite to submitting a Biologics License Application, or BLA, to the FDA and similar marketing applications to other regulatory authorities, for each product candidate and, consequently, the ultimate approval and commercial marketing of any product candidates. We do not know whether any of our clinical trials will be completed on schedule, if at all.

We may experience delays in initiating or completing clinical trials and preclinical studies. We also may experience numerous unforeseen events during, or as a result of, any ongoing and future clinical trials that we

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conduct that could delay or prevent our ability to receive marketing approval or commercialize our product candidates, including:

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We could also encounter delays if a clinical trial is suspended, placed on clinical hold or terminated by us, the IRBs of the institutions in which such trials are being conducted, or the FDA or other regulatory authorities or recommended for suspension or termination by the Data Safety Monitoring Board, or DSMB, for such trial. A suspension or termination may be imposed due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols, inspection of the clinical trial operations or trial site by the FDA or other regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a product or treatment, failure to establish or achieve clinically meaningful trial endpoints, changes in governmental regulations or administrative actions or lack of adequate funding to continue the clinical trial. Many of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of our product candidates. Further, the FDA or other regulatory authorities may disagree with our clinical trial design and our interpretation of data from clinical trials, or may change the requirements for approval even after they have reviewed and commented on the design for our clinical trials. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses and many companies that believed their product candidates performed satisfactorily in preclinical studies and clinical trials nonetheless failed to obtain FDA approval.

Our product development costs will increase if we experience delays in clinical testing or marketing approvals. Our preclinical studies or clinical trials may not begin as planned, may need to be restructured or may not be completed on schedule, or at all. Significant preclinical studies or clinical trial delays also could shorten any periods during which we may have the exclusive right to commercialize our product candidates and may allow our competitors to bring products to market before we do, potentially impairing our ability to successfully commercialize our product candidates and harming our business and results of operations. Any delays in our preclinical or clinical development programs may harm our business, financial condition and prospects significantly.

Interim top-line and preliminary data from our clinical trials that we announce or publish from time to time may change as more patient data become available and are subject to audit and verification procedures that could result in material changes in the final data.

From time to time, we may publish interim top-line or preliminary data from our clinical trials. Interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available. Additionally, we make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data. Preliminary or top-line data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data we previously published. As a result, interim and preliminary data should be viewed with caution until the final data are available. Adverse differences between preliminary or interim data and final data could significantly harm our business prospects. Further, the FDA and other regulatory authorities may not accept or agree with our assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate or product and our business in general.

Positive results from early preclinical and clinical studies of our product candidates are not necessarily predictive of the results of later preclinical studies and any clinical trials of our product candidates. If we cannot replicate the positive results from our earlier preclinical and clinical studies of our product candidates in our later preclinical studies and any clinical trials, we may be unable to successfully develop, obtain regulatory approval and commercialize our product candidates.

Any positive results from our preclinical and early clinical studies of our engEx product candidates may not necessarily be predictive of the results in later preclinical studies and clinical trials. Similarly, even if we are able to complete our planned preclinical studies or clinical trials of our product candidates according to our current development timeline, the positive results from such preclinical studies and clinical trials may not be replicated in our subsequent preclinical studies or later-stage clinical trials.

There is a high failure rate for drugs and biologics proceeding through clinical trials. Many companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in clinical trials after achieving positive results in early-stage development and we cannot be certain that we will not face similar setbacks. These

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setbacks have been caused by, among other things, preclinical and other nonclinical findings made while clinical trials were underway or safety or efficacy observations made in clinical trials, including previously unreported adverse events. Moreover, preclinical, nonclinical and clinical data are often susceptible to varying interpretations and analyses, which may delay, limit or prevent regulatory approval. Many companies that believed their product candidates performed satisfactorily in preclinical studies and clinical trials nonetheless failed to obtain FDA approval.

Our clinical trials or those of our future collaborators may reveal significant adverse events not seen in our preclinical studies and may result in a safety profile that could inhibit regulatory approval or market acceptance of any of our product candidates.

There is typically an extremely high rate of attrition due to failure of product candidates proceeding through clinical trials. Following repeated dosing some patients may develop antibodies to our exosome therapeutics. These antibodies could reduce the efficacy of our exosome therapeutics or result in undesirable side effects. Product candidates in later stages of clinical trials also may fail to show the desired safety and efficacy profile despite having progressed through preclinical studies and initial clinical trials. A number of companies in the biopharmaceutical industry have suffered significant setbacks in advanced clinical trials due to lack of efficacy or unacceptable safety issues, notwithstanding promising results in earlier trials. Most product candidates that commence clinical trials are never approved as products and there can be no assurance that any of our clinical trials will ultimately be successful or support further clinical development of any of our product candidates.

We initiated clinical trials for our first two product candidates, exoSTING and exoIL-12, in September 2020, and expect to initiate clinical trials on exoASO-STAT6 in the first half of 2022, and there may be serious adverse events or undesirable side effects related to these or other of our product candidates. If significant adverse events or other side effects are observed in any of our clinical trials, we may have difficulty recruiting patients to our clinical trials, patients may drop out of our trials or we may be required to limit development to certain uses or subpopulations in which the serious adverse events, undesirable side effects or other characteristics are less prevalent, less severe, or more acceptable from a risk-benefit perspective, or to abandon the trials or our development efforts of one or more product candidates altogether. We, the FDA or other applicable regulatory authorities or an IRB may suspend clinical trials of a product candidate at any time for various reasons, including a belief that subjects in such trials are being exposed to unacceptable health risks or adverse side effects. The FDA or other regulatory authorities could also deny approval of our product candidates for any or all targeted indications. Some potential therapeutics developed in the biotechnology industry that initially showed therapeutic promise in early-stage trials have later been found to cause side effects that prevented their further development. Even if the side effects do not preclude the drug from obtaining or maintaining marketing approval, undesirable side effects may inhibit market acceptance of the approved product due to its tolerability versus other therapies. Any of these developments could materially harm our business, financial condition and prospects.

If we encounter difficulties enrolling patients in our clinical trials, our clinical development activities could be delayed or otherwise adversely affected.

We may experience difficulties with patient enrollment in our clinical trials for a variety of reasons. The timely completion of clinical trials in accordance with their protocols depends, among other things, on our ability to enroll a sufficient number of patients who remain in the study until its conclusion. The enrollment of patients depends on many factors, including:

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In addition, our clinical trials compete with other clinical trials for product candidates that are in the same therapeutic areas as our product candidates and this competition will reduce the number and types of patients available to us because some patients who might have opted to enroll in our trials may instead opt to enroll in a trial being conducted by one of our competitors. Since the number of qualified clinical investigators is limited, we expect to conduct some of our clinical trials at the same clinical trial sites that some of our competitors use, which will reduce the number of patients who are available for our clinical trials in such clinical trial site. Moreover, because our product candidates represent a departure from more commonly used methods for our targeted therapeutic areas, potential patients and their doctors may be inclined to use conventional therapies, rather than enroll patients in any ongoing or future clinical trials we may conduct.

Delays in patient enrollment may result in increased costs or may affect the timing or outcome of our clinical trials, which could prevent completion of these trials and adversely affect our ability to advance the development of our product candidates.

Negative developments in the field of exosomes could damage public perception of any product candidates that we develop, which could adversely affect our ability to conduct our business or obtain regulatory approvals for such product candidates.

Exosome therapeutics are novel and unproven therapies, with no exosome therapeutic approved to date. Exosome therapeutics may not gain the acceptance of the public or the medical community. To date, other efforts to leverage natural exosomes have generally demonstrated an inability to generate exosomes with predictable biologically active properties or to manufacture exosomes at suitable scale to treat more than a small number of patients. Some studies used natural exosomes without an intended or understood mechanism of action or pharmacology. Other studies included payloads but generated inconclusive results. Our success will depend on our ability to demonstrate that our engEx exosomes can overcome these challenges.

If one of our current or future product candidates is unable to successfully target a certain cell type or pathway and establish proof of concept in a certain disease, it may indicate that we will not be able to apply our engEx Platform to other diseases mediated by that cell type or pathway. This may also indicate a decrease in the probability of our success for other targets using the same modality in the same or different cell types, as well as for our engineered exosome approach more generally. Such failures could negatively affect the public or medical community’s perception of our engEx Platform and exosome therapeutics in general.

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Additionally, our success will depend upon physicians who specialize in the treatment of diseases targeted by our product candidates, if approved, prescribing treatments that involve the use of our product candidates, if approved, in lieu of, or in addition to, existing treatments with which they are more familiar and for which greater clinical data may be available. Adverse events in clinical trials of our product candidates or in clinical trials of others developing similar products and the resulting publicity, as well as any other adverse events in the field of exosome therapeutics, could result in a decrease in demand for any product that we may develop. These events could also result in the suspension, discontinuation, or clinical hold of, or modification to, our clinical trials. Any future negative developments in the field of exosomes and their use as therapies could also result in greater governmental regulation, stricter labeling requirements and potential regulatory delays in the testing or approvals of our product candidates. Any increased scrutiny could delay or increase the costs of obtaining marketing approval for any of our product candidates.

We may not be successful in our efforts to utilize our engEx Platform to identify and develop additional engEx product candidates. Due to our limited resources and access to capital, we must choose to prioritize development of certain product candidates, such as our initial focus on developing exoSTING and exoIL-12, which may prove to be wrong choices and may adversely affect our business.

A key element of our strategy is utilizing our engEx Platform to generate multiple engEx product candidates. Although we are developing numerous engEx product candidates targeting various cell types and indications and carrying a wide range of biologically active drug molecules, in addition to the engEx product candidates we are currently developing, we may fail to identify viable new engEx product candidates for clinical development for a number of reasons. For example, while we believe our engEx Platform engineered exosomes is capable of enhancing the value of several established drug modalities, such as nucleic acid therapeutics, including antisense oligonucleotides, or ASOs, siRNA, miRNA, mRNA, gene therapy and gene editing, we have not yet successfully advanced an engEx exosomes incorporating these drug modalities into clinical trials, and we may not be successful in developing engineered exosomes to deliver any of these types of molecules. If we fail to identify additional potential engEx product candidates, our business could be materially harmed.

Research programs to pursue the development of our engEx product candidates and using our engEx Platform to design and identify new engEx product candidates and disease targets require substantial technical, financial and human resources whether or not they are ultimately successful. Our engEx Platform and research programs may initially show promise in identifying potential indications and/or product candidates, yet fail to yield results for clinical development for a number of reasons, including:

If any of these events occur, we may be forced to abandon our research or development efforts for a program or programs, which would have a material adverse effect on our business, financial condition or results of operations. Because we have limited financial and managerial resources, we focus on research programs and product candidates that we identify for specific indications among many potential options. For example, we have focused our initial clinical development of exoSTING and exoIL-12 on a limited set of cancer indications. As a result, we may forego or delay pursuit of opportunities with other product candidates or for other indications that later prove to have greater commercial potential or a greater likelihood of success. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. Our spending on current and future research and development programs and product candidates for specific

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indications may not yield any commercially viable medicines. If we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that product candidate through collaboration, licensing or other royalty arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights to such product candidate.

Accordingly, there can be no assurance that we will ever be able to identify additional therapeutic opportunities for our product candidates or to develop suitable potential product candidates through internal research programs, which could materially adversely affect our future growth and prospects. We may focus our efforts and resources on potential product candidates or other potential programs that ultimately prove to be unsuccessful, which would be costly and time-consuming.

We face significant competition from other biotechnology and pharmaceutical companies and our operating results will suffer if we fail to compete effectively.

The biotechnology and pharmaceutical industries, including in the exosome therapeutics area, are characterized by rapid growth, a dynamic landscape of competitive product candidates and a strong reliance on intellectual property. We face competition from a variety of organizations, including larger pharmaceutical companies, specialty biotechnology companies, academic research institutions, governmental agencies, as well as public and private institutions.

There are several companies that are currently developing exosome-based therapeutics for use in a variety of indications, from cancer to rare disease, to regenerative medicine. Broadly, the development of exosome therapeutics can be segregated into two groups: those that use (a) unmodified cell-derived exosomes and (b) engineered and ex vivo modified exosomes.

Unmodified cell-derived exosomes generally rely on the intrinsic therapeutic activity of cargo in exosomes collected from a specific producer cell type. Typically, these producer cells are stem cells or other precursor cells and the exosomes are generally used in regenerative medicine, immuno-suppression and central nervous system modulation. The mechanism of action for these exosomes is not well-understood and may rely on one or more cargo types including miRNAs, mRNAs, and/or surface proteins. Although none of our engEx product candidates relies on unmodified exosomes isolated from producer cells, there is potential competition in the application and uses of our engEx product candidates with those based on unmodified exosomes. Competitors using unmodified cell-derived exosomes include Aegle Therapeutics Corp., ArunA Biomedical, Inc., or ArunA, Capricor Therapeutics, Inc. and ReNeuron Group plc. In addition, several small-scale clinical studies using unmodified cell-derived exosomes have been initiated, often led by academic investigators, for a variety of indications including cancer, immune diseases and stroke.

All of our existing and anticipated engEx product candidates use exosomes that are produced from modified cells and/or are loaded ex vivo with various biologically active molecules. We understand that our competitors using engineered and ex vivo modified exosomes plan to use their candidates in numerous therapeutic applications, some of which may directly compete with our engEx product candidates and early programs. Competing therapeutic applications include cancer, metabolic diseases, various rare diseases, central nervous system disorders, neuromuscular disorders, diseases of the immune system and infectious diseases. Competitors using engineered and ex vivo loaded exosomes include ArunA, AstraZeneca plc, or AstraZeneca, Evox Therapeutics Ltd. and PureTech Health plc.

We also face competition outside of the exosome therapeutics field, including from some of the largest pharmaceutical companies and other specialty biotechnology companies. Our lead engEx product candidates, exoSTING and exoIL-12, face competition from numerous companies.

In the STING agonist space: Bristol-Myers Squibb Company, or BMS; Merck & Co., Inc., or Merck; Takeda Pharmaceutical Company Limited; Eisai Co., Ltd., or Eisai; Nimbus Therapeutics, Inc.; GlaxoSmithKline plc, or GSK; F-star Therapeutics, Limited, or F-star; Synlogic, Inc., or Synlogic; Mavupharma, Inc. (acquired by AbbVie Inc.) and others. Merck, BMS, Eisai, GSK, F-star and Synlogic have initiated clinical trials using STING agonists in cancer patients. Additionally, there are several STING agonist programs that have been described in the literature that are owned or being developed by academic institutions that may soon enter clinical trials.

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In the IL-12 space: Astellas Pharma Inc.; Celsion Corporation, or Celsion; Cytix, Inc., or Cytix; Dragonfly Therapeutics Inc.; Eli Lilly and Company; MedImmune, LLC (acquired by AstraZeneca), or MedImmune; Immvira Co Ltd.; Inovio Pharmaceuticals, Inc.; Merck; Moderna, Inc., or Moderna; Neumedicines, Inc., or Neumedicines; OncoSec Medical Incorporated, or OncoSec; Rubius Therapeutics, Inc.; Repertoire Immune Medicines, Inc.; Ziopharm Oncology, Inc., or Ziopharm; and others. The IL-12 programs from Ziopharm, OncoSec, Neumedicines, Celsion, Cytix, Merck and MedImmune are currently being used in clinical trials.

We also face competition related to the therapeutic areas and biologically active molecules we plan to engineer onto or into our engEx exosomes. As described above, our engEx Platform is amenable to creating exosomes capable of delivering and/or displaying numerous classes of biologically active molecules. For each of these therapeutic areas and molecule classes we face competition from numerous large pharmaceutical companies and specialty biotechnology companies.

We also face competition outside of the exosome therapeutics field from large pharmaceutical companies and specialty biotechnology companies using synthetic drug delivery systems such as liposomes, lipid nanoparticles and other non-viral delivery approaches, including Alnylam, Arbutus Biopharma, Arcturus Therapeutics, Inc., Intellia, Ipsen Group, Johnson & Johnson, Luye Pharma Group, Moderna and others. These include marketed products and those that are currently in clinical development.

In addition, many of our current or potential competitors, either alone or with their collaboration partners, have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials and marketing approved products than we do. Mergers and acquisitions in the biopharmaceutical industry may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs. Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any products that we may develop. Our competitors also may obtain FDA or other regulatory approval for their products more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we are able to enter the market. The key competitive factors affecting the success of all of our programs are likely to be their efficacy, safety, convenience and availability of reimbursement.

If our current programs are approved for the indications for which we are currently planning clinical trials, they may compete with other products currently under development. Competition with other related products currently under development may include competition for clinical trial sites, patient recruitment and product sales.

We also may face competition in the United States for our product candidates, if approved, from therapies sourced from foreign countries that have placed price controls on pharmaceutical products. In the United States, the FDA issued a final guidance document outlining a pathway for manufacturers to obtain an additional National Drug Code, or NDC, for an FDA-approved drug that was originally intended to be marketed in a foreign country and that was authorized for sale in that foreign country. The market implications of the final guidance are unknown at this time. Proponents of drug reimportation may attempt to pass legislation that would directly allow reimportation under certain circumstances. Legislation or regulations allowing the reimportation of drugs, if

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enacted, could decrease the price we receive for any products that we may develop and adversely affect our future revenues and prospects for profitability.

In addition, as a result of the expiration or successful challenge of our patent rights, we could face more litigation with respect to the validity and/or scope of patents relating to our competitors’ products and our patents may not be sufficient to prevent our competitors from commercializing competing products.

We may develop exoSTING, exoIL-12, exoASO-STAT6 and potential future product candidates in combination with other therapies and safety or supply issues with combination-use products may delay or prevent development and approval of our product candidates.

We may develop exoSTING, exoIL-12, exoASO-STAT6 and potential future product candidates, in combination with one or more cancer or other therapies, both approved and unapproved. Even if any product candidate we develop were to receive marketing approval or be commercialized for use in combination with other existing therapies, we would continue to be subject to the risk that the FDA or similar regulatory authorities outside of the US could revoke approval of the therapy used in combination with our product candidate, or that safety, efficacy, manufacturing or supply issues could arise with these existing therapies. Combination therapies are commonly used for the treatment of cancer and we would be subject to similar risks if we develop any of our product candidates for use in combination with other drugs or for indications other than cancer. We may choose to combine multiple cancer therapies on one exosome, which could enhance the risk of safety-related issues. Similarly, if the therapies we use in combination with our product candidates are replaced as the standard of care for the indications we choose for any of our product candidates, the FDA or similar regulatory authorities outside of the US may require us to conduct additional clinical trials. The occurrence of any of these risks could result in our own products, if approved, being removed from the market or being less successful commercially.

We will not be able to market and sell exoSTING, exoIL-12, exoASO-STAT6 or any product candidate we develop in combination with any such unapproved cancer therapies that do not ultimately obtain marketing approval. The regulations prohibiting the promotion of products for unapproved uses are complex and subject to substantial interpretation by the FDA and other government agencies. In addition, there are additional risks similar to the ones described for our products currently in development and clinical trials that result from the fact that such cancer therapies are unapproved, such as the potential for serious adverse effects, delay in their clinical trials and lack of FDA approval.

Furthermore, we cannot be certain that we will be able to obtain a steady supply of such cancer therapies for use in developing combinations with our product candidates on commercially reasonable terms or at all. Any failure to obtain such therapies for use in clinical development and the expense of purchasing therapies in the market may delay our development timelines, increase our costs and jeopardize our ability to develop our product candidates as commercially viable therapies.

If the FDA or similar regulatory authorities outside of the US do not approve these other drugs or revoke their approval of, or if safety, efficacy, manufacturing or supply issues arise with, the drugs we choose to evaluate in combination with exoSTING, exoIL-12, exoASO-STAT6 or any product candidate we develop, we may be unable to obtain approval of or market exoSTING, exoIL-12, exoASO-STAT6 or any product candidate we develop.

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Even if a product candidate we develop receives marketing approval, it may fail to achieve the degree of market acceptance by physicians, patients, third-party payors and others in the medical community necessary for commercial success.

If any engEx product candidate we develop receives marketing approval, whether as a single agent therapeutic or in combination with other therapies, its commercial success will depend upon its degree of market acceptance by physicians, patients, third-party payors and others in the medical community. For example, other cancer treatments like chemotherapy, radiation therapy and immunotherapy are well-established in the medical community and doctors may continue to rely on these therapies instead of therapies derived from our engEx Platform, if approved. If the engEx product candidates we develop do not achieve an adequate level of acceptance, we may not generate significant product revenues and we may not become profitable. The degree of market acceptance of any product candidate, if approved for commercial sale, will depend on a number of factors, including:

Even if a potential product displays a favorable efficacy and safety profile in preclinical studies and clinical trials, market acceptance of the product will not be fully known until after it is launched. If our product candidates do not achieve an adequate level of acceptance following regulatory approval, if ever, we may not generate significant product revenue and may not become profitable.

Acquisitions, collaborations or other strategic partnerships may increase our capital requirements, dilute our stockholders, cause us to incur debt or assume contingent liabilities and subject us to other risks.

We are engaged in various collaborations and strategic partnerships and may evaluate additional partnerships or potential acquisitions, including licensing or acquiring biologically active molecules to load into or onto our engineered exosomes, complementary products, intellectual property rights, technologies or businesses. For example, our partnership with Jazz Pharmaceuticals Ireland Limited, or Jazz, focuses on the research, development and commercialization of exosome therapeutics to treat cancer. Our existing collaborations and partnerships and any future potential acquisition, collaboration or strategic partnership may entail numerous risks, including:

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