til-20211231

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

For the fiscal year ended December 31, 2021

For the transition period from ________ to ________

Commission file number 001-40215

Instil Bio, Inc.

(Exact name of registrant as specified in its charter)

(Address of Principal Executive Offices)

(972) 499-3350

Registrant's telephone number, including area code

Not Applicable

(Former name, former address and former fiscal year, if changed since last report)

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

Title of each class Trading Symbol(s) Name of each exchange on which registered

Common Stock, $0.000001 par value per share TIL The Nasdaq Stock Market LLC

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 and posted on its corporate web site, if any, 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 files). Yes☒ No ☐

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

Large accelerated filer ☐ Accelerated filer ☐

Non-accelerated filer ☒ Smaller reporting company ☒

Emerging growth company ☒

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 7(a)(2)(B) of the Securities 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 ☒

As of June 30, 2021, the last business day of the registrant’s most recently completed second fiscal quarter, the aggregate market value of the registrant’s common stock held by non-affiliates of the registrant was approximately $1,070.6 million, based on the closing price of the registrant’s common stock on the Nasdaq Global Select Market on June 30, 2021 of $19.32 per share.

Indicate the number of shares outstanding of each of the issuer’s classes of common stock, as of the latest practicable date:

Class of Common Stock Outstanding at

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s definitive proxy statement to be filed with the Securities and Exchange Commission (SEC) subsequent to the date hereof pursuant to Regulation 14A in connection with the registrant's 2022 Annual Meeting of Stockholders, are incorporated by reference into Part III of this Annual Report on Form 10-K. Such proxy statement will be filed with the SEC not later than 120 days after the conclusion of the registrant's fiscal year ended December 31, 2021.

TABLE OF CONTENTS

Page

Part I

Item 1. Business 2

Item 1A. Risk Factors 39

Item 1B. Unresolved Staff Comments 101

Item 2. Properties 101

Item 3. Legal Proceedings 101

Item 4. Mine Safety Disclosures 101

Part II

Item 7A. Quantitative and Qualitative Disclosures About Market Risk 114

Item 8. Financial Statements and Supplementary Data 115

Item 9A. Controls and Procedures 143

Item 9B. Other Information 144

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections 144

Part III

Item 10. Directors, Executive Officers and Corporate Governance 145

Item 11. Executive Compensation 145

Item 14. Principal Accounting Fees and Services 145

Part IV

Item 15. Exhibits, Financial Statement Schedules 146

Part I

Item 1. Business.

Overview

We are a clinical-stage biopharmaceutical company focused on developing an innovative cell therapy pipeline of autologous tumor infiltrating lymphocyte, or TIL, therapies for the treatment of patients with cancer. We have assembled an accomplished team with a successful track record in the development, manufacture, regulatory approval and commercialization of multiple cell therapies. Using our optimized and scalable manufacturing process, we are advancing our lead TIL product candidate, ITIL-168, for the treatment of advanced melanoma. Based on the clinical results from a compassionate use program with a TIL product that was manufactured using a prior version of the ITIL-168 manufacturing process, we submitted an investigational new drug application, or IND, to the U.S. Food and Drug Administration, or the FDA, and were authorized to initiate a Phase 2 trial in late 2021 with expected topline safety and efficacy data in 2023, which we believe could support a biologics license application, or BLA submission. We plan to initiate a Phase-1 trial of ITIL-168 in additional indications with unmet medical need, including cutaneous squamous cell carcinoma, or CSCC, non-small cell lung cancer, or NSCLC, head and neck squamous cell carcinoma, or HNSCC, and cervical cancer, in 2022. ITIL-168 will be manufactured in our company-operated in-house manufacturing facilities for both our clinical trials and commercial sales, if approved.

We are also developing a novel class of genetically engineered TIL therapies using our Co-Stimulatory Antigen Receptor, or CoStAR, platform. These modified TILs still rely on their native, patient-specific T cell receptors, or TCRs, to bind to tumor neoantigens, but have been enhanced to express novel CoStAR molecules, which bind to shared tumor-associated antigens and provide potent costimulation to T cells within the tumor microenvironment. We believe that the ability of CoStAR to augment the activation of TILs upon native TCR-mediated recognition of tumor neoantigens has the potential to bring TIL therapy to patients with cancer types that have been historically resistant to immunotherapy. We anticipate filing an investigational new drug, or IND, application for our lead CoStAR-TIL product candidate, ITIL-306, in 2022.

We believe the critical advantage of TIL therapy over other cell therapies relates to the intrinsic and diverse anti-tumor reactivity of TILs. Unlike most cell therapies in development for solid tumors, which only recognize a single target antigen shared across a diverse patient population, TILs are polyclonal and therefore have the ability to recognize the broad set of antigens unique to each patient. This comprehensive polyclonality helps overcome a major limitation of cell therapies, such as CAR-Ts and TCR-Ts, by providing the requisite diversity to match the marked heterogeneity of solid tumors.

The successful use of TIL therapy to treat solid tumors was first published in 1988 by Steven A. Rosenberg, M.D., Ph.D., and his colleagues from the National Cancer Institute, or NCI, who demonstrated remissions in patients with advanced melanoma who had been treated with TILs. Since these initial reports, clinical studies of TILs have expanded significantly. In a study published in Annals of Oncology in 2019, U. Dafni and colleagues conducted a meta-analysis of clinical trials of TIL therapies published between 1988 and 2016, which reported an overall remission rate, or ORR, of 41% and a complete remission, or CR, rate of 12% in 410 heavily pretreated patients with metastatic melanoma. As shown below, in patients for whom detailed follow-up was available, the CRs were found to be remarkably durable, with only one of 28 patients experiencing disease recurrence.

TIL Therapy Demonstrated Durable CRs

in Patients with Melanoma in Clinical Trials Between 1988 and 2016

In addition to melanoma, TIL therapy has also demonstrated efficacy in multiple other solid tumors, including NSCLC, HNSCC, and cervical cancer. However, despite these compelling clinical results, TIL therapy has largely been limited to the academic or compassionate use settings due to the lack of an industrialized and scalable process for the manufacture of these products.

By leveraging our team’s experience, we are executing on our plan to efficiently launch in-house capabilities of manufacturing, process development, clinical operations, regulatory strategy and research and development. We have created a robust, reproducible process to generate well-characterized and commercially viable TIL product candidates that we believe will provide patients with long-term therapeutic benefit.

Our Strengths

Our goal is to become the leader in the design, manufacture and delivery of TIL therapies to patients with cancer. We believe the following strengths will enable us to achieve this goal:

Highly experienced team. Our senior management team and a large fraction of our operational staff have extensive experience in cell therapy, withmany having participated in the design and execution of the clinical development, manufacture and regulatory approval of Yescarta and Tecartus at Kite Pharma/Gilead, as well as the development of other clinical-stage cell therapy product candidates. In addition, our team and scientific advisors have a track record of successfully leading the technology discovery, process development, GMP manufacturing and clinical operations functions at other cell therapy companies.

Robust clinical development experience with TILs. Members of our team have been generating and improving TIL therapy for over a decade, and aTIL product manufactured by us has been used in the treatment of patients with refractory melanoma through a compassionate use program at the Christie Hospital in Manchester, United Kingdom,

which is the largest single-site cancer center in Europe. In the 21 patients treated through the compassionate use program using a TIL product that was manufactured using a prior version of the ITIL-168 manufacturing process, we observed a CR in four patients (19%) and a partial remission, or PR, in 10 patients (48%), resulting in an ORR of 67%. In addition, four patients reported SD, resulting in a disease control rate, or DCR, of 86%. Ten of the 21 patients have died from complications arising from disease progression. The results from the compassionate use program do not provide a guarantee that ITIL-168 will be deemed to be safe or effective for the treatment of melanoma or additional indications, and extensive clinical testing and regulatory approval will be required before ITIL-168 can be commercially marketed for the treatment of melanoma. Based on these results, together with our development and manufacturing expertise, we intend to transform TIL therapy into what we believe will be a scalable, convenient and effective option for patients with cancer.

Optimized and scalable manufacturing process. We have developed a manufacturing process customized for autologous TIL therapies to maximizemanufacturing success rate and potential for clinical efficacy beyond current practices. To ensure product quality and consistency, we have chosen to maintain full control of the entire manufacturing process, from the procurement of tumor samples through the shipping of the final product, without any outsourcing of core manufacturing process or quality control testing steps. Our process includes the optimized cryopreservation of both the digested tumor at the beginning to preserve cell viability and potency and the final product at the end to provide increased shelf life. Importantly, our cryopreservation process also provides significant scheduling flexibility for physicians and patients.

Company-operated in-house manufacturing facilities. We believe we are well positioned to execute on our clinical development plans and serve theU.S. and European markets with our existing and planned infrastructure. We have invested and plan to continue to invest in our manufacturing capabilities on two continents, with one facility in the United States in Tarzana, California for both clinical and commercial manufacturing and another in Manchester, United Kingdom for clinical manufacturing. By controlling and operating our manufacturing facilities on two continents, we believe we have the unique ability to more efficiently implement continuous improvements into our operations and to readily provide therapies to patients across a broad geography. With planned capacity across both of our facilities, we expect to have sufficient doses for all our clinical trials, as well as to meet the initial commercial demand of ITIL-168, if approved.

Strong capitalization. Since 2019, we have financed our operations with $719.0 million in net proceeds raised in our initial public offering and private placements of convertible preferred stock to date. This funding hasenabled us to assemble a team with experience across the entire spectrum of cell therapy development, including clinical development and operations, regulatory submissions, process engineering, quality analytics, manufacturing and strategic commercialization planning.

Our Pipeline

We are building an innovative pipeline of optimized TIL product candidates, including both unmodified and genetically engineered TILs, for the treatment of patients with cancer. We own worldwide rights to all our product candidates. Our current pipeline is summarized in the diagram below.

Our lead product candidate, ITIL-168, is an autologous TIL therapy that we are initially developing for the treatment of PD-1-inhibitor relapsed or refractory advanced melanoma. We are utilizing an optimized and scalable manufacturing process that we believe will differentiate the profile of ITIL-168 from other cell therapies, including other TIL therapies. Our process for ITIL-168 manufacturing begins with the complete digestion of the tumor tissue, which releases all TILs from the tumor microenvironment and enables cryopreservation of the digested tumor at the beginning of the process to preserve cell viability and potency. Additionally, we cryopreserve the final product to provide increased shelf life. Our cryopreservation process at both the beginning and end of the manufacturing process provides significant scheduling flexibility for physicians and patients.

We have generated preliminary safety and efficacy data in advanced melanoma in the context of a compassionate use program in the United Kingdom, using a TIL product that was produced with a prior version of the ITIL-168 manufacturing process. Twenty-one patients with stage IV metastatic cutaneous melanoma were treated in this compassionate use program between 2011 and 2019. Treatment led to an ORR of 67%, including four patients (19%) who achieved CR and ten patients (48%) who achieved a PR. The DCR, which included patients with CR, PR or SD, was 86%. Based on these clinical results and our discussions with the FDA, we submitted IND for ITIL-168 and were authorized to initiate a Phase 2 trial in late 2021 with expected topline safety and efficacy data in 2023, which we believe could support a BLA submission. Additionally, in 2022, we intend to initiate Phase 1 trials of ITIL-168 in tumor types where evidence of immune cell recognition and elimination of cancer cells has been observed, such as CSCC, NSCLC, HNSCC and cervical cancer.

We are also developing genetically engineered TIL product candidates modified with CoStAR to augment the activation of TILs in the tumor microenvironment. In preclinical studies, CoStAR+ T cells demonstrated markedly increased activity as compared to normal T cells, including enhanced cytokine expression and proliferative capacity. CoStAR’s modular architecture can be adapted to potentially target any cell surface antigen, which will allow us to develop additional CoStAR-TIL product candidates that enhance TIL function in multiple solid tumors.

Our lead CoStAR-TIL product candidate, ITIL-306, expresses a CoStAR molecule designed to recognize folate receptor alpha, or FOLR1, a tumor-associated antigen that is expressed on numerous solid tumors, including ovarian cancer, uterine cancer, NSCLC and renal cancer. We believe that ITIL-306 has the potential to increase anti-tumor activity due to its ability to improve proliferation and enhance cytokine secretion while retaining the specificity and polyclonality of TILs. We intend to submit an IND for ITIL-306 in 2022 and initiate a Phase 1 trial in 2022 to evaluate safety, feasibility and preliminary efficacy in multiple tumor types.

wide variety of tumor types, including stomach, colorectal, pancreatic, breast and other cancers. We intend to select our next CoStAR-TIL product candidate for IND-enabling studies in 2022.

Our History and Team

We were founded in August 2018, and in early 2019, we in-licensed our foundational TIL technology from Immetacyte Ltd. and subsequently raised our Series A round of funding from Curative Ventures. In March 2020, we acquired Immetacyte Ltd., which had been manufacturing a TIL product for the compassionate use program at the Christie Hospital in the United Kingdom from 2011 to 2019. Since 2019, we have financed our operations with $719.0 million in net proceeds raised in our initial public offering and private placements of convertible preferred stock to date.

We have assembled a team of industry veterans with deep experience in conducting all phases of development, from early stage clinical trials through regulatory approval across multiple regions, as well as in the commercial manufacture and marketing of cell therapies. Our management team consists of entrepreneurs, physicians and scientists with prior experience at cell therapy and oncology companies such as Kite Pharma/Gilead, Amgen, Pfizer, Genentech and Johnson & Johnson, among others.

Our Strategy

Our goal is to leverage our optimized and scalable manufacturing process to deliver innovative, life-saving TIL therapies to patients with cancer. In order to achieve this goal, our strategy involves the following key elements:

Background on TILs

Overview of Engineered T Cell Therapies

T cells are one of the key cell types of the immune system. Their roles include targeting cells that pose a threat to our health, such as infected or cancerous cells, for direct killing, as well as producing soluble mediators of immunity, like cytokines, to improve or otherwise modulate the overall immune response. T cells recognize and target these cells for killing through the engagement of the TCR by peptide antigens presented on the surface of the target cell by the major histocompatibility complex, or MHC. T cell therapies can be generated from peripheral blood collected and separated via leukapheresis to isolate T cells that are then genetically modified to express relevant TCRs or CARs. Alternatively, T cell therapies can be generated from tumor-infiltrating lymphocytes, or TILs, collected from a resected tumor.

CAR-T and TCR-T therapies are cell products composed of T cells that have been genetically engineered to recognize a specific cancer-related antigen on the surface of tumor cells. Recently, multiple CAR-T therapies such as Yescarta, Tecartus and Kymriah, which each target the B-cell antigen CD19, have achieved regulatory approval after demonstrating efficacy in the treatment of several kinds of B-cell malignancies. Despite these successes in blood cancers, CAR-T and TCR-T therapies have shown limited efficacy in the treatment of solid tumors. In addition to the general lack of anti-tumor activity, serious and potentially fatal toxicities commonly seen with these therapies have been observed in multiple clinical trials in solid tumors. These side effects include those related to normal tissue distribution of the target antigen, as well as antigen-independent toxicities such as cytokine release syndrome, neurotoxicity and prolonged pancytopenia. For these reasons, there are currently no approved CAR-T or TCR-T therapies for the treatment of solid tumors.

Tumor heterogeneity is a major obstacle in successfully treating solid tumors with single-antigen targeting modalities like CAR-Ts and TCR-Ts. Individual cancer cells within tumors are clonally diverse and thus display significant differences in the profile of antigens they express. As most CAR-T and TCR-T therapies are engineered to target a single antigen, they lack the ability to address the profound antigenic heterogeneity found within solid tumors. Patients with solid tumors who have been treated with these therapies are at increased risk of clonal escape, which is the growth of tumor cells that do not express the antigen targeted by the therapy. Clonal escape, also known as target-negative relapse, is a well-described mechanism by which single antigen targeting therapies fail in the treatment of cancer.

Other limitations of both CAR-T and TCR-T therapies are related to tissue distribution of the target antigen itself. CAR-T cells target cell surface proteins that are often found on both normal tissues and tumors, leading to on-target, off-tumor toxicity. In the case of anti-CD19 CAR-T cell products, the complete elimination of normal B cells is an expected side effect and results in possibly permanent immunosuppression. Also, because CAR-T therapies can only target surface antigens, they are not able to recognize intracellular tumor-specific proteins, which significantly limits the number of potential molecules to target. In contrast, TCRs recognize all cellular antigens that have been presented by MHC molecules, enabling T cells to recognize and attack cancer cells, including those expressing either intracellular or membrane-anchored tumor-specific proteins. However, despite the broader antigen recognition capabilities of TCR-Ts, the MHC-dependent mechanism requires careful tissue matching between the transgenic TCR and the patient, thus limiting the addressable patient population to only those patients with the appropriate MHC alleles. Finally, the targeted antigen for either CAR-T or TCR-T therapies must be shared broadly between patients. As a result, these therapies are not able to recognize unique, patient-specific antigens that may otherwise be attractive targets.

Overview of TIL Therapies

The application of TILs to treat solid tumors began in 1988, when these cells were first used as an experimental therapy at the U.S. National Cancer Institute. At that time, Steven A. Rosenberg, M.D., Ph.D. and his colleagues published results demonstrating melanoma regression in patients who had been treated with TILs grown ex vivo. Over the past 30 years, interest in TIL therapy for melanoma and other solid tumors has expanded significantly beyond academia, with dozens of academic and industry-sponsored clinical trials ongoing currently, ranging from Phase 1 exploratory trials of TILs in combination with a checkpoint inhibitor to Phase 3 randomized trials comparing TILs with established therapies.

A meta-analysis of clinical trials evaluating TIL therapies was published in the journal Annals of Oncology in 2019 and reported an ORR of 41% in 410 heavily pretreated patients with metastatic melanoma. Twelve percent of patients achieved CR with long-term durability, with only one of 28 patients experiencing disease recurrence.

We believe the following key factors are critical to the development of a patient-specific TIL-based therapy for the treatment of solid tumors:

Polyclonal recognition of tumor-specific antigens.TILs are activated to recognize and kill tumor cells based on their ability to bind to tumor-specific antigens. Unlike CAR-T cells and other engineered cell therapies that recognize only a single target antigen that is required to be both expressed on the surface of all tumor cells and shared across different patients, TILs are polyclonal and have the ability to recognize the broad set of antigens that are unique to each individual patient. This comprehensive, patient-specific polyclonality provides TIL therapies with the requisite diversity to respond to the marked clonal heterogeneity of the patient’s tumors, addressing a major limitation of cell therapies such as CAR-Ts and TCR-Ts.

Optimized processing and manufacturing methods. TIL therapies rely on patient-derived material obtained from each patient’s resected tumor. Theprocessing methods for the freshly removed tumor tissue immediately following resection impact the characteristics of the final TIL product, including its potential efficacy. Streamlined and timely tumor procurement, processing and transportation is required to ensure manufacturing and clinical success.

The composition of the TIL population. TILs are immune cells naturally present in some tumors and composed of two types of T cells: CD8+ andCD4+ T cells. CD8+ T cells are cytotoxic T cells that are able to directly kill tumor cells. CD4+ T cells are T helper cells that secrete cytokines and engage in other activities to stimulate and recruit other immune cells, including other T cells, macrophages and dendritic cells, to tumor sites. Correlative studies have shown that high levels of T cells in tumors and surrounding tissues are associated with improved prognosis in a number of solid tumors, and the presence of both types of T cells is necessary for effective tumor control.

Our Approach

Our goal is to become the leader in the design, manufacture and delivery of TIL therapies to patients with cancer. We believe that the key elements that differentiate us include our highly experienced team, our optimized and scalable manufacturing process and our company-operated in-house manufacturing facilities.

Our Highly Experienced Team

We have assembled a team with extensive experience in the manufacture, clinical development and regulatory approval of cell therapies. Our process and engineering teams bring rigor to managing changes to our manufacturing processes based on their recognized track record in cell therapy research, development and commercialization. Our clinical operations team has developed CAR-T and TCR-T therapies in clinical trials across a wide variety of diseases, lines of therapy and patient populations across multiple geographies under the supervision of the FDA, the European Medicines Agency, or the EMA, and other leading regulatory agencies. We have operational know-how regarding tissue collection, chain of identity and custody, logistics and administration of autologous cell therapy products. Our team has a track record of successfully completing regulatory audits across multiple clinical trial sites, external vendors and internal processes. Notably, many members of our team were instrumental in the manufacture, clinical development and regulatory approvals of Yescarta and Tecartus.

Our Optimized and Scalable Manufacturing Process

We have designed our TIL manufacturing process to maximize manufacturing success rate and potential for clinical efficacy beyond current industry practices. To ensure product quality and consistency, we have chosen to maintain full control of the entire manufacturing process, from the procurement of tumor samples through the shipping of the final product, without any outsourcing of core manufacturing process or quality control testing steps. Our process includes the optimized cryopreservation of both the fully digested tumor at the beginning of the manufacturing process to preserve cell viability and potency and the final product at the end of the manufacturing process to provide increased shelf life. Importantly, our cryopreservation process also provides significant scheduling flexibility for physicians and patients, which may improve our ability to provide treatment to patients in a timely manner.

With our team’s extensive experience in the commercialization of cell therapies, we understand the feasibility and the value of continuous improvements in manufacturing. We have designed a robust quality system focused on compliance that includes routine testing for release, documentation of our processes and the assessment of the impact of any changes on final product performance. The quality of this data is essential as regulators rely on it to understand the relationship between products that may have been generated by modified or updated manufacturing procedures. In addition to our continuous refinements, we are also focused on longer-term manufacturing innovation initiatives that will drive generational changes to our manufacturing methods. For example, we are developing an automated, standardized platform to minimize manual processing and provide in-line process measurements that can be used to shorten manufacturing times, increase manufacturing success and reduce costs.

Another key component of the manufacturing process for cell therapies is the release criteria used to characterize the final product. We have developed and are validating a robust potency assay aimed at understanding the mechanism of action of our TIL therapies. Based on initial discussions with regulatory agencies regarding our potency assay and other release methods to support our IND approval, we believe that our assay methodology and final product release criteria will continue to satisfy guidelines and meet the expectations of the FDA and other regulatory authorities in support of BLA submission. Additionally, we have developed robust assays for purity, safety and dose designed to assure quality of our product. In addition to our release assays, we have generated a comprehensive package of characterization data as indicated by our IND approval.

Our Company-Operated In-house Manufacturing Facilities

We have expanded our manufacturing capabilities at our facilities in Manchester, United Kingdom, which has been operational since 2011, and are investing in expanding our manufacturing capabilities in the United States in

Tarzana, California, which became operational in the first half of 2022. Both facilities are fully controlled and operated by us, which will allow us to more efficiently introduce new product candidates and implement next-generation manufacturing technologies. In addition, by having facilities on two continents, we believe we have the ability to provide therapies, if approved, to patients across a broad geography as well as to continuously improve our operations.

Our clinical facility in Tarzana, which is expected to begin producing patient doses in the first half of 2022, has flexible modular technology using prefabricated modular cleanroom pods, enabling future process scalability and minimizing delays associated with the need for onsite construction. These modular cleanroom pods also provide the required segregation to allow for simultaneous manufacturing of distinct autologous products, such as ITIL-168 and ITIL-306, within the same manufacturing facility. Our clinical capacity is currently estimated up to approximately 150 patient doses per year with regulatory approval of our expanded facility in Manchester, U.K. Our Tarzana manufacturing facility will initially have a clinical capacity of up to 350 patient doses per year. We believe the aggregate capacity from these facilities will be sufficient for all of our planned clinical development activities. We are further expanding our capacity in Tarzana, California by establishing a commercial facility which we believe will be sufficient to meet the initial commercial demand of ITIL-168, if approved. With planned expansion of our commercial facility, we believe we could be able to support commercial demand of over 3,000 lots per year.

Our TIL Manufacturing Process

Our manufacturing process comprises three distinct and serial stages: (i) tumor processing, which includes tissue harvesting and cryopreservation, (ii) TIL generation, which includes the outgrowth and rapid expansion phases, and (iii) final product processing, which includes formulation and cryopreservation. We believe our novel approach to these three stages provides us with key advantages compared to historical approaches, as summarized below.

Historical Approach Our Novel Approach Our Potential Advantages

Tumor Processing

The starting material for our TIL product candidates is personalized with TILs isolated from a surgically excised sample of the patient’s tumor. These tumor samples contain tumor cells, stromal cells and TILs. When TIL therapy was first developed in an academic research setting, the operating room in which the patient underwent the tumor resection procedure was in close physical proximity to the laboratory in which the TIL therapy was made.

Therefore, both the time required and the complexity of the transportation from operating room to manufacturing site were minimized. As TIL product candidates advance from single-institution clinical trials into registration-enabling global trials with multiple clinical sites and centralized manufacturing, controls for the stability of the removed tumor tissue must be instituted. We have developed a proprietary process in which the resected tissue is immediately processed and cryopreserved at one of our regional hubs located close to the clinical site, ensuring that our starting material is stable and preserved for shipment to one of our in-house manufacturing facilities for further processing.

The first step in our process involves fully dissociating the tumor tissue into a cell suspension through a combination of enzymatic digestion and gentle, automated agitation of the tissue. This initial step in our proprietary process has been designed to harvest all of the TILs embedded within the tumor without impacting cell viability. Our process is distinguished from typical manufacturing processes that start with manually minced fragments of tumor tissue. Our technique ensures that the greatest possible diversity of unique TCRs are preserved from the time of resection through the entire manufacturing process, as shown below:

Our Tumor Processing Method Releases and Preserves

All of the TILs from Tumor Samples

The rapid and reproducible stabilization of starting tumor material is crucial in enabling a scalable commercial process for treatment of patients across a broad geography. Logistical challenges, including coordination of patient scheduling with hospital availability, transportation of fresh tumor material and availability of manufacturing slots, have represented a significant barrier to the successful commercialization of autologous cell therapies. The process and infrastructure that we have developed to industrialize tumor procurement both preserves the starting tumor material and provides flexibility by allowing us to schedule tumor resection and TIL manufacturing independently from each other. Furthermore, once the starting material is cryopreserved, it can be stored for an extended period under controlled conditions before manufacturing begins, which reduces the risk of manufacturing failures due to tissue degradation and provides treatment flexibility for physicians and patients. Our novel approach will allow for the harvest of starting tumor material during routine biopsies or debulking surgeries for use in future TIL therapies.

In order to minimize the time from initial tumor resection to the processing, freezing and shipping of the tumor tissue, as part of our clinical trial, we plan to deploy a team of trained TIL recovery specialists to staff regional processing hubs strategically located near major treatment centers. The ability to have our specially trained staff take control of the tumor tissue as early in the process as possible and to process it using our proprietary methods helps ensure that the TILs in the starting material are of the highest possible quality and meet our manufacturing standards.

TIL Generation

The TIL generation step in our process includes the outgrowth and rapid expansion phases, as shown below, to ensure that our final TIL product contains an expanded population of TILs to maximize potential clinical efficacy.

The Outgrowth and Rapid Expansion of Our TILs Result in a Final Product

Containing an Expanded Population of TILs

Outgrowth Phase. Once the cryopreserved tumor sample has reached one of our in-house manufacturing facilities, we thaw the suspension andculture the TILs and tumor cells together to promote the identification of tumor neoantigens by the TILs. This TIL outgrowth phase is designed to offer maximum exposure of the diverse and complete population of TILs to the clonally heterogenous tumor cells.

The complete tumor digestion that we utilize during the tumor processing step liberates all TILs from the tumor. During the outgrowth phase, all TILs are exposed to uniform concentrations of Interleukin-2, or IL-2, a potent T cell growth factor, in the cell suspension and freely associate with tumor cells. Our digestion process allows all of the harvested TILs to be collected and transitioned into the rapid expansion phase, or REP, of manufacturing and included in the final product. In contrast, the fragmentation method, in which a tumor specimen is manually minced into small fragments that are then cultured whole during outgrowth, relies on the migration of TILs out of the fragments by following an IL-2 gradient. Only those cells that successfully leave the tumor fragment and enter the bulk culture are collected and used to seed the REP of manufacturing; those that remain within the tumor fragment are discarded at the end of the outgrowth phase and thus are prevented from inclusion in the REP and final product. By the end of the TIL outgrowth phase in our process, the culture is predominantly composed of viable tumor-educated T cells, including CD8+ cytotoxic T cells and CD4+ helper T cells, and ready for further processing.

Rapid Expansion Phase. In the REP of manufacturing, we optimize the culture conditions to be conducive to the expansion of T cells that make upthe final cell dose of the TIL therapy. We stimulate the cells with IL-2, OKT3, an anti-CD3 antibody that activates all TCRs, as well as feeder cells, which are peripheral blood mononuclear cells that support optimal growth conditions. Once sufficient expansion of the cell product has been reached to achieve what we define to be a therapeutic dose, the culture is harvested and prepared for final formulation and cryopreservation.

We believe our optimized and scalable manufacturing process provides several key advantages, including:

•The ability to capture and preserve maximum health and diversity of each patient’s TILs by completely digesting and immediately cryopreserving the tumor sample near the clinical site to ensure stability during transportation to one of our in-house manufacturing facilities;

•A limited number of manual processing steps and a functionally closed manufacturing process to increase process reliability and scalability; and

•Flexibility to coordinate fresh tissue harvest with manufacturing availability through cryopreservation of both the starting material as well as the final product.

•A limited number of manual processing steps and a functionally closed manufacturing process to increase process reliability and scalability; and

•Flexibility to coordinate fresh tissue harvest with manufacturing availability through cryopreservation of both the starting material as well as the final product.

These attributes give us confidence that we will be able to deliver TIL-based therapies at a level of robustness, quality, consistency and scale not previously achieved by other TIL-based approaches.

Our Product Candidates

ITIL-168

Our lead TIL product candidate, ITIL-168, is an autologous TIL therapy that we are initially developing for the treatment of advanced melanoma. We have generated preliminary safety and efficacy data in advanced melanoma in the context of a compassionate use program using a TIL product that was produced with a prior version of the ITIL-168 manufacturing process. Twenty-one patients with stage IV metastatic cutaneous melanoma were treated between 2011 and 2019. Treatment led to an ORR of 67%, including four patients (19%) who achieved CR and ten patients (48%) who achieved PR. The DCR, which included patients with CR, PR or SD, was 86%. Based on these clinical results and our discussions with the FDA, we submitted an IND for ITIL-168 and, were authorized to initiate a Phase 2 trial in late 2021 with expected topline safety and efficacy data in 2023, which we believe could support a BLA submission. In addition to melanoma, we intend to initiate a Phase 1 trial of ITIL-168 in tumor types where evidence of immune cell recognition and elimination of cancer cells has been observed, such as CSCC, NSCLC, HNSCC and cervical cancer, in 2022.

Melanoma Overview

Melanoma is the most lethal form of skin cancer, accounting for the majority of skin cancer deaths. It arises from a malignant proliferation of melanocytes in the skin. The National Cancer Institute estimated that there would be more than 100,000 diagnoses of melanoma and 6,850 deaths from melanoma in the United States in 2020. Localized cutaneous melanoma is the fifth most common malignancy in the United States, and the incidence is rising. Most patients diagnosed with localized cutaneous melanoma have an excellent prognosis; however, in patients with distant metastatic spread of their disease, the 5-year survival rate is only 27%.

The primary risk factor for development of melanoma is exposure to ultraviolet, or UV, light, including sunlight and tanning beds. UV light and other environmental toxins can cause DNA damage, which, if not repaired, leads to an increased number of genetic mutations. In part due to this type of DNA damage, melanoma typically contains a high number of mutations. Furthermore, approximately half of melanomas have oncogenic driver mutations, such as alterations in the gene for proto-oncogene B-Raf, or BRAF. Both oncogenic driver and other mutations are an important differentiating feature between melanoma cells and healthy cells and form the pathophysiologic basis for recently developed therapeutic options.

Approximately one-half of cutaneous melanomas have an activating mutation in the BRAF gene. BRAF activates the mitogen-activated protein kinase, or MAPK, pathway, which accelerates the transformation of the cell into a cancer cell. BRAF inhibitors have demonstrated various positive clinical outcomes in melanoma, including tumor regression and survival improvement. Because many patients with BRAF mutations also have mutations in other oncogenes, the combination of a BRAF inhibitor with an inhibitor of mitogen-activated extracellular signal-regulated kinase, or MEK, an enzyme in the MAPK pathway, has been shown to further improve response rates and survival as compared with BRAF inhibition alone. Multiple BRAF inhibitors, such as vemurafenib (Zelboraf), dabrafenib (Tafinlar) and encorafenib (Braftovi), and MEK inhibitors, such as trametinib (Mekinist), cobimetinib (Cotellic) and binimetinib (Mektovi), have been approved for the treatment of metastatic melanoma.

More recently, multiple novel immunotherapies known as checkpoint inhibitors have been approved to treat advanced melanoma. These inhibitors block pathways such as PD-1/PD-L1 and CTLA4, which serve as negative regulators of T cell function. These groundbreaking therapies have changed the treatment landscape for metastatic melanoma and have dramatically improved both response rates and survival for patients.

Patients who are ineligible for surgery are typically treated with these systemic therapies. However, despite the significant response rates achieved with BRAF/MEK inhibitors and immunotherapies, a large proportion of patients either do not respond at all or develop resistance following an initial response and require additional therapy. Patients with melanoma that is refractory to or has relapsed following these treatments face a dearth of therapeutic options. There is no standard approach to the management of these patients and the limited number of agents used in this setting have shown poor response rates, high toxicity and limited survival benefit, as shown below.

Summary of Published Trials of Treatments for Patients with Advanced Melanoma

Lead Author(Year of Publication) N Treatment ORR Toxicity OverallSurvival

Zimmer (2017) 37 Ipilimumab + nivolumab 21% 33% discontinuation 55% (1 year)

According to the scientific literature, TIL therapy is considered one of the most effective treatments for patients with advanced melanoma, including following the failure of checkpoint inhibitors and BRAF/MEK inhibitors. However, because of the complexity in scaling autologous cell therapies, including TIL therapy, access to this potentially life-saving treatment has been limited to patients who are enrolled in clinical trials or treated under compassionate use. Furthermore, the majority of these TIL therapy clinical trials have been conducted in single academic centers with little standardization in the manufacturing methods used to isolate, activate and expand the TILs that comprise the final product. We believe our optimized process will enable the standardization and scaling of the manufacture of our lead TIL product candidate, ITIL-168, to provide significant clinical benefit for patients with advanced melanoma.

Our Solution: ITIL-168

We initiated a global, multi-center Phase 2 clinical trial of ITIL-168 in PD-1-inhibitor relapsed or refractory advanced melanoma in late 2021 and intend to initiate a multi-center Phase 1 clinical trial of ITIL-168 in several solid tumor types in 2022. Our process for ITIL-168 begins with the procurement of the resected tumor by one of our trained specialists. At one of our regional processing hubs located near the clinical site, the resected tumor is placed into a sterile bag containing media and tissue digestion enzymes. The bag is then heat-sealed and its contents are digested through a process of gentle agitation and enzymatic activity to generate a homogeneous cell suspension containing tumor cells and TILs. This proprietary method allows for the complete digestion of the tumor tissue and

releases all of the TILs from the tumor microenvironment. The cell suspension is then cryopreserved and shipped to one of our in-house manufacturing facilities, where it is thawed. The process of activating and expanding the TILs is then initiated. Upon completion of manufacturing, the final product candidate is formulated and cryopreserved for shipment back to the clinical site. Following treatment with lymphodepleting chemotherapy and ITIL-168, the patient is treated with IL-2 to support the further proliferation of ITIL-168 in vivo. The manufacturing period takes approximately 24-25 days based on our current processes. Our manufacturing and treatment process for ITIL-168 is summarized in the graphic below:

The ITIL-168 Manufacturing and Treatment Process

A preclinical study of TILs made from three separate patients using a process similar to ITIL-168 consistently killed tumor cells. In addition, this study showed dose-dependent anti-tumor activity in vitro with evidence of tumor killing even at low TIL to tumor cell ratios, as shown below:

A Preclinical Study Demonstrated Dose-Dependent Anti-Tumor Activity In Vitro

Clinical Data from Compassionate Use Program

We have generated preliminary safety and efficacy data from a compassionate use program in the United Kingdom in advanced melanoma using a TIL product that was manufactured using a prior version of the ITIL-168 manufacturing process. The compassionate use program was authorized under a Manufacturing Specials license from the Medicines and Healthcare products Regulatory Agency. Individual patients were referred by their local oncologists to Professor Robert Hawkins, MBBS FRCP, Ph.D., our Chief Strategy Advisor and a well-known medical oncologist and cell therapy investigator at the Christie Hospital in Manchester, United Kingdom, for evaluation and treatment.

Between 2011 and 2019, a total of 21 patients with stage IV metastatic cutaneous melanoma received approximately the same treatment regimen we intend to evaluate in our clinical trials of ITIL-168: lymphodepleting chemotherapy, TIL infusion and post-TIL IL-2 treatment. The majority of these patients had metastases to the lung and other non-CNS sites, referred to as stage M1c disease, or brain metastases, referred to as stage M1d disease, including 14 patients who had metastatic lesions in more than three sites and seven patients who had brain metastases. These patients were referred to Dr. Hawkins after being treated with and failing an average of three prior systemic therapies. Over 90% of the patients had failed the CTLA4 inhibitor ipilimumab, and 12 patients had experienced disease progression on or following treatment with a PD-1 inhibitor as well as ipilimumab. More than half of the patients had a BRAF mutation and had progressed on a BRAF inhibitor.

As shown in the table below, treatment with TIL therapy led to an ORR of 67% in these 21 patients, including four patients (19%) who achieved CR and 10 patients (48%) who achieved PR. The DCR, which included 4 patients with SD in addition to those with CRs and PRs, was 86%. Of these 21 patients, 15 were followed up with CT and/or MRI at regular intervals in a manner consistent with standard RECIST 1.1 methodology; in this subgroup of patients, the ORR was 53% and the CR rate was 13%. The other six patients were followed with non-RECIST imaging modalities like PET/CT as well as clinical monitoring. Two of these six patients had developed melanoma that was unequivocally refractory to the BRAF inhibitor dabrafenib in combination with MEK inhibitor therapy immediately prior to TIL treatment but were continued on dabrafenib, with brief interruptions for tumor harvest and TIL infusion, to prevent the rapid disease progression that often accompanies abrupt dabrafenib discontinuation. Both patients developed durable responses following TIL treatment. One patient, who had also failed prior ipilimumab and PD-1 blockade, achieved a PR that lasted approximately 14 months from TIL infusion during which time dabrafenib was continued. The second patient was treated with dabrafenib for approximately three months following TIL infusion, at which point the dabrafenib was stopped. This patient achieved a PR at approximately 12 months after TIL infusion that converted to a durable CR that was ongoing for over four years after TIL infusion at the time of data cutoff.

Summary of Responses in All Patients Treated in Compassionate Use Program (n=21)

n (%)

Overall remission rate 14 (67%)

Partial remission rate 10 (48%)

Complete remission rate 4 (19%)

Disease control rate 18 (86%)

Eight of the 14 responders were still alive as of the data cutoff date of December 31, 2019, with all four patients with CRs remaining without disease progression, as shown below.

Treatment with TIL Therapy Led to Long-term Survival of Patients with Metastatic Melanoma in Compassionate Use Program

One of the responding patients in the compassionate use program was a 16-year-old male with widely metastatic and bulky (sum of lesion diameters = 103mm), BRAF-mutated melanoma that was refractory to three prior lines of therapy, including ipilimumab, a CTLA4 inhibitor, and dabrafenib, a BRAF inhibitor. Following treatment with TIL therapy, this patient experienced a rapid reduction in his disease burden, as shown in the images below. Over the following year, repeated scans confirmed continued reduction in his systemic and brain metastases, and he subsequently achieved CR and has remained without disease progression for over seven years.

Ongoing Complete Remission at 7+ Years in a 16-Year-Old Patient with

Metastatic Melanoma in Compassionate Use Program

Among the 12 patients who had previously failed at least one PD-1 inhibitor as well as ipilimumab, seven patients (58%) achieved a remission, including one (8%) who achieved CR. The DCR, which included two patients with SD, was 75%, as shown in the table below.

Summary of Responses in Patients with PD-1 and CTLA4 Inhibitor Relapsed or Refractory Melanoma in Compassionate Use Program (n=12)

n (%)

Overall remission rate 7 (58%)

Partial remission rate 6 (50%)

Complete remission rate 1 (8%)

Disease control rate 9 (75%)

The median time to response in all 21 patients was under 2 months and the median overall survival was 21.3 months, as shown in the Kaplan-Meier survival graph below. The results from the compassionate use program do not provide a guarantee that ITIL-168 will be deemed to be safe or effective for the treatment of melanoma or additional indications, and extensive clinical testing and regulatory approval will be required before ITIL-168 can be commercially marketed for the treatment of melanoma.

Survival of Patients with Advanced Melanoma Treated with TIL Therapy in Compassionate Use Program

Safety

Overall, the safety findings associated with the TIL regimen of lymphodepletion, TIL transfusion and post-TIL IL-2 treatment was consistent with the published literature of TIL therapy in patients with melanoma. Side effects were largely transient, self-limited and generally attributable to the lymphodepleting chemotherapy regimen and post-TIL IL-2 treatment. The most common adverse events, or AEs, after the TIL infusion were transient low blood counts and physiological manifestations of IL-2, including fever, tachycardia and edema. There were no deaths deemed related to the treatment regimen. As of the data cutoff date, 10 of 21 patients had died due to complications arising from disease progression.

AEs experienced by patients in this compassionate use program were not systematically graded by the treating physicians nor was AE attribution or seriousness consistently collected. Rather, AEs were summarized by signs and symptoms and according to the time of onset relative to the treatment sequence. The most frequently reported AEs during the lymphodepleting chemotherapy period were neutropenia (nine patients, 43%) and nausea (four patients, 19%). All other AEs were reported in one patient (5%) each. The most frequently reported AEs after TIL infusion were thrombocytopenia (13 patients, 62%), pyrexia (12 patients, 57%) and rigors (nine patients, 43%). Neutropenia and tachycardia were experienced by six patients (29%) each; pulmonary edema and vascular leak were each observed in five patients (24%). Rash was observed in four patients (19%) and atrial fibrillation, cardiovascular instability, chest infection and oedema were each observed in three patients (14%). All other AEs occurred in two or fewer patients (<10%).

Clinical Development Plans

Based on the results from the compassionate use program, we submitted an IND and were authorized to proceed with a Phase 2 trial of ITIL-168 in patients with PD-1-inhibitor relapsed or refractory advanced melanoma in the late 2021. We anticipate obtaining topline safety and efficacy data in 2023, and we believe this Phase 2 trial, if successful, has the potential to support the submission of a BLA to the FDA and a Marketing Authorization Application to the EMA.

We designed our Phase 2 trial to enroll approximately 130 patients who have relapsed or refractory cutaneous melanoma. There are three patient cohorts in the study design: Cohort 1 (approximately 80 patients) includes patients who have failed treatment with a PD-1 inhibitor and, if applicable, a BRAF inhibitor; Cohort 2 (approximately 25 patients) includes patients who discontinued PD-1 inhibitor therapy due to intolerable toxicity; Cohort 3 (approximately 25 patients) includes patients who had an unsatisfactory response to prior PD-1 inhibitor but have not yet experienced disease progression. Patients will undergo surgery to remove a small amount of their tumor to initiate the manufacturing process. Once the patient-specific ITIL-168 is fully manufactured and sent back to the clinical site, patients will be treated with lymphodepleting chemotherapy. ITIL-168 infusion will be followed by treatment with IL-2 to support the further proliferation of ITIL-168 in vivo. The primary endpoint of this trial will be ORR, with secondary endpoints focusing on additional aspects of safety and efficacy.

Clinical Development for ITIL-168 in Additional Tumor Types

We intend to initiate clinical trials of ITIL-168 in other solid tumor types where evidence of immune cell recognition and elimination of cancer cells has been observed. We plan to evaluate ITIL-168 for the treatment of relapsed or refractory NSCLC, HNSCC and cervical cancer. Third-party TIL therapy has demonstrated clinical proof of concept in each of these tumor types, with an ORR of 31% reported in a clinical trial of a third-party TIL therapy for the treatment of HNSCC, an ORR of 25% reported in a clinical trial of a third-party TIL therapy for the treatment of NSCLC, and an ORR of 44% reported in a clinical trial of a third-party TIL therapy for the treatment of cervical cancer. We also plan to evaluate ITIL-168 for the treatment of relapsed or refractory, locally advanced or metastatic CSCC. All of these tumor types continue to have an unmet medical need. In 2019, the annual mortality of NSCLC, HNSCC and cervical cancers in the U.S. surpassed 120,000, 10,000, and 4,000, respectively. We expect to file another amendment to our IND for ITIL-168 and initiate a multi-indication Phase 1 trial in 2022. Following this trial, if successful, we anticipate opening Phase 2 trials within each of these four tumor types to evaluate the safety and efficacy of ITIL-168 in these indications.

CoStAR: A Co-stimulatory Platform to Genetically Engineer TILs

We are developing a novel class of genetically engineered TIL product candidates designed to express Co-Stimulatory Antigen Receptor, or CoStAR, molecules to augment the activation of TILs in the tumor microenvironment, potentially leading to an increase in anti-tumor activity. We believe that the ability of CoStAR to enhance the activation of TILs upon recognition of tumor neoantigens has the potential to bring TIL therapy to patients with cancer types that historically have been resistant to immunotherapy. In preclinical studies, we observed that CoStAR+ T cells demonstrated markedly increased activity as compared to normal T cells, including enhanced cytokine expression and proliferative capacity. We are leveraging the optimized and scalable manufacturing process that we have developed for ITIL-168 to develop manufacturing process steps specific to CoStAR-TIL therapies.

We plan to evaluate CoStAR-TIL therapies in several tumor types where TILs have not yet established proof of concept or responses to TIL therapy have been poor. We anticipate submitting an IND for our lead CoStAR-TIL product candidate, ITIL-306, in 2022.

Role of Co-stimulation in T Cell Activation

Activation of T cells typically requires more than the recognition of an antigenic peptide bound to the MHC on the surface of a target cell. Maximum T cell activation generally requires both this antigen-specific signal and a second, antigen-independent signal known as costimulation. Costimulation occurs when a costimulatory molecule

on the surface of the T cell binds to its ligand on the target cell at the same time that the TCR is engaging with the antigen presented by the MHC. The requirement for costimulation also applies to T cell therapies. For example, first generation CAR-T therapies did not contain any additional costimulatory molecules, as shown below, and therefore relied on endogenous co-stimulation for enhanced activity within the tumor microenvironment. As a result, the anti-tumor activity of these first-generation products was low. Subsequent generations of CAR-T therapies included one or more costimulatory domains, which have been shown to increase their anti-tumor activity. However, these therapies are still bound by the limitations of single-antigen targeting, including on-target, off-tumor toxicities.

Costimulatory Domains in First Generation vs.

Next-Generation CAR-T Therapies

Design and Intended Function of CoStAR

Our CoStAR platform encompasses a class of novel CARs designed to increase the anti-tumor activity of our TIL product candidates by providing potent co-stimulation via two intracellular costimulatory domains that are linked by a transmembrane sequence to an extracellular single chain variable fragment, or scFv. When CoStAR is expressed on the surface of TILs, the scFv is designed to bind to commonly expressed, shared tumor-associated antigens and thereby deliver a potent costimulatory signal to the T cell. This costimulatory signal is only relevant when the TIL’s native TCR engages a tumor-specific neoantigen on the surface of the tumor cell, as shown below. In preclinical studies, we did not observe any measurable effects of CoStAR engagement of the shared tumor-associated antigen on the T cell without concomitant TCR recognition of a tumor neoantigen.

The main difference between CoStAR and second or later generation CARs is that CoStAR is designed to exclusively induce co-stimulation. This effect is achieved by the elimination of the CD3ζ signaling domain that is uniformly included in CAR-T products. Absence of the CD3ζ domain renders CoStAR ligation alone unable to lead to T cell activation or cytolytic activity. Similar to ITIL-168, the full activation of CoStAR+ T cells is first dependent on the recognition of tumor-specific antigens by the native TCR. The CoStAR modification only serves to augment the activation of the T cells once TCR binding has occurred. In preclinical studies, we did not observe any measurable effects of CoStAR engagement of the shared tumor-associated antigen on the T cell without concomitant TCR recognition of a tumor neoantigen.

We believe the separation of function between tumor recognition and activation in our CoStAR-TILs provides the following key advantages compared to CAR-T therapies:

Increased potency without a change in specificity. The introduction of a CAR to a T cell fundamentally changes its specificity to target cells thatexpress the antigen bound by the scFv of the CAR. Because the target antigen is not unique to individual tumor cells, CAR-T cells kill any cells that express this antigen, including healthy cells. This lack of discrimination often results in on-target, off-tumor toxicity, as observed with anti-CD19 CAR-T therapies that eliminate normal B cells that express CD19, causing prolonged immunosuppression. In contrast, CoStAR does not change the specificity of TILs, as T cell activation is still entirely dependent on the recognition by the cell’s native TCR of a unique tumor neoantigen presented by the target cell. CoStAR strictly provides the necessary costimulatory signal for full T cell activation. Through the selection of the specific scFv incorporated into the CoStAR architecture, costimulation is triggered in a tumor-specific manner, providing a microenvironment-specific signal leading to increased TIL activation.

Retention of polyclonal antigen recognition. Our CoStAR-TILs rely on the unique endogenous TCRs expressed by each T cell to recognize theheterogeneous set of tumor neoantigens that are presented by tumor cells. With CoStAR-TIL therapy, the T cells isolated directly from the patient’s tumor have been naturally selected by the immune system and preserved by our manufacturing process to target patient-specific neoantigens. We believe the ability to target multiple antigens is critical to the success of cell therapies in solid tumors due to the intra-tumor heterogeneity of cancer cells in solid tumors and the limited success observed with single-antigen cell therapy approaches to date.

Enhanced cytokine secretion and profile. Our CoStAR-TIL product candidates are designed to secrete high levels of activating cytokines into theirsurrounding microenvironment upon the engagement of unique tumor neoantigens by the TILs’ native TCRs in combination with the engagement of the target by CoStAR. Additionally, the production of immunosuppressive cytokines is reduced. We believe that these properties of our CoStAR-TILs will stimulate immune cell migration into tumors, which may, in turn, drive additional immune reaction to the tumor, resulting in the conversion of poorly immunogenic tumors with few endogenous immune cells into inflamed tumors with a broad array of activated immune cell subsets. Such inflamed tumors have been shown to be more amenable to treatment with immunotherapies and to have better prognosis.

Broad platform targeting shared tumor-associated antigens. A defining feature of our CoStAR platform is its expected safety profile. Unlikeconventional ADC or CAR-T therapies, CoStAR’s engagement with the cell expressing its target antigen alone does not trigger its elimination. This key attribute allows us to consider a wide array of antigens to target with our CoStAR-TIL product candidates with fewer concerns related to safety risk associated with normal tissue expression. In addition to the tumor-associated antigens commonly targeted by other therapeutic modalities, such as HER2, CoStAR may have the potential to target other antigens, including those with extensive normal tissue expression.

Our CoStAR Platform

During our development of the CoStAR platform, we empirically designed and tested a number of sequences containing various costimulatory domains, either as single domains or as pairs of domains, to identify the most potent architecture using a variety of target antigens. We found that the inclusion of a particular configuration of two

costimulatory domains led to markedly enhanced cytokine secretion, cell survival and proliferation in vitro as compared to the other tested variants.

We observed increased expression of certain pro-inflammatory cytokines, such as IL-2, without increased expression of immunosuppressive cytokines, such as IL-10, that are known to be detrimental to T cells and other immune subsets, as shown below, which we believe is due to the design of the signaling domains in CoStAR. We believe that CoStAR’s ability to increase pro-inflammatory cytokines with no significant rise in immunosuppressive ones creates a favorable immunological milieu that may promote a robust anti-tumor response.

CoStAR Increased Pro-inflammatory Cytokines

And Did Not Increase Immunosuppressive Cytokines

In multiple third-party CAR-T therapy clinical trials, post-infusion expansion of T cells has been shown to correlate with deep and durable clinical responses in patients. The in vitro expansion of T cells demonstrated in our preclinical studies, even in stringent culture conditions that lack supplemental IL-2, provides preclinical evidence of the improved proliferative capacity of CoStAR+ T cells. As shown below, CoStAR+ T cells responded to target cells that expressed OKT3, an anti-CD3 antibody that activates all TCRs, and the CoStAR target with increased survival and proliferation as compared to CoStAR- T cells.

CoStAR+ T Cells Showed Increased Survival and Proliferation of Cells in the Absence of IL-2

Our preclinical studies of CoStAR+ T cells have demonstrated the potential of CoStAR-TIL therapies to increase anti-tumor activity compared to conventional TIL therapies. Specifically, the CoStAR platform:

•Retained the anti-tumor TCR repertoire of the starting TIL population, thus reducing the potential for normal tissue toxicity;

•Demonstrated markedly increased survival and growth potential and reduced dependence on supplemental IL-2 in response to target cells expressing OKT3 and the CoStAR target; and

•Secreted high levels of immune-activating cytokines like IL-2 without increased expression of immunosuppressive cytokines, which we believe offers the potential for a potent bystander effect in the tumor microenvironment.

Our Lead CoStAR-TIL Product Candidate, ITIL-306

Our first CoStAR-TIL product candidate, ITIL-306, is an autologous TIL therapy genetically engineered to express a CoStAR molecule that recognizes FOLR1. FOLR1 is a tumor-associated antigen that is expressed on numerous solid tumors, including ovarian, uterine, NSCLC and renal cancers. As shown in the immunohistochemical, or IHC, stains below, FOLR1 is found to be expressed at high levels in numerous solid tumor indications and its expression in normal tissue is minimal. The FOLR1-CoStAR candidate stimulates T cells through a novel combination of intracellular domains from CD40 and CD28, which was shown to markedly outperform other combinations of costimulatory domains in various in vitro assays. ITIL-306 will be manufactured with a 21-day manufacturing process that has demonstrated robust transduction of TILs in our process development studies.

FOLR1 is Expressed by Numerous Solid Tumors,

as Assessed by mRNA and Protein

To validate that FOLR1-CoStAR TILs are robustly activated only in the presence of FOLR1 and native TCR stimulation, we assessed the ability of CoStAR+ T cells to secrete IL-2 in an in vitro study. Cytokine secretion is a classical measure of activation of T cells and represents a key mechanism by which CoStAR+ T cells enhance the tumor microenvironment and proliferation of TILs. These CoStAR+ T cells were cultured with target cells that were engineered to express OKT3, FOLR1, neither of these molecules, or both.

As shown below, the culture with OKT3-expressing target cells yielded a modest increase in IL-2 secretion over baseline. The addition of CoStAR costimulation, as shown by the FOLR1 expression in the target cells, led to an approximately 10-fold increase in IL-2 secretion. Importantly, ligation of CoStAR by FOLR1 alone in the absence of TCR engagement led to no measurable increase over baseline IL-2 secretion, supporting that the delivery of costimulation through the CoStAR molecule alone does not activate T cells. This finding supports our hypothesis that CoStAR will limit the on-target, off-tumor toxicity that is often found with classical CAR-T therapies, while enhancing T cell activation within the tumor.

CoStAR+ T Cells Enhanced Secretion of IL-2 in the Presence of Both FOLR1 and Activated TCRs

We intend to submit an IND for ITIL-306 in 2022. Further preclinical and manufacturing development of ITIL-306 will inform the final clinical development plan and first-in-human study design. We anticipate initiating a Phase 1 trial in 2022 to evaluate preliminary safety, feasibility and efficacy in multiple tumor types.

Additional CoStAR-TIL Programs

The modular nature of our CoStAR platform allows for multiple product candidates to be developed with minimal changes to the fundamental architecture of the molecule. We have generated a number of constructs containing antigen-binding domains directed against different tumor-associated antigens that are expressed by a wide variety of tumor types, including stomach, colorectal, pancreatic, breast and other cancers. We have identified construct families for our next CoStAR-TIL product candidate, and we intend to select our next CoStAR-TIL product candidate for IND-enabling studies in 2022.

Commercialization Plan

We are in the process of building our U.S. commercial and medical affairs infrastructure and intend to build our own global commercialization capabilities over time in certain geographies for our TIL product candidates, including ITIL-168 and ITIL-306. If any of our TIL product candidates are approved, we expect to commercialize those products with an experienced sales, marketing and distribution organization, including a national specialty oncology sales force. As additional product candidates advance through our pipeline, our commercial plans will evolve as we consider elements such as the market potential.

Competition

The biotechnology and pharmaceutical industries are characterized by the rapid evolution of technologies and understanding of disease etiology, intense competition and a strong emphasis on intellectual property. We believe that our approach, strategy, scientific and manufacturing capabilities, know-how and experience provide us with competitive advantages. However, we expect substantial competition from multiple sources, including major pharmaceutical, specialty pharmaceutical, and existing or emerging biotechnology companies, academic research institutions and governmental agencies and public and private research institutions worldwide. Many of our competitors, either alone or through collaborations, have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals and marketing approved products than we do. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These entities also compete with us in recruiting and retaining qualified scientific, manufacturing and management

personnel and establishing clinical trial sites and patient enrollment in clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs. As a result, our competitors may discover, develop, license or commercialize products before or more successfully than we do.

We face competition from segments of the pharmaceutical, biotechnology and other related markets that pursue the development of TIL or other cell therapies for the treatment of solid tumors. Companies that are developing TIL therapies include Iovance Biotherapeutics Inc., Adaptimmune Therapeutics, Plc., Achilles Therapeutics, Ltd., Intima Bioscience, Inc., Nurix Therapeutics, Inc., KSQ Therapeutics, Inc., Obsidian Therapeutics, Inc., PACT Pharma, Inc., Lyell Immunopharma, and Neogene Therapeutics, B.V. In addition, we may face competition from companies focused on CAR-T and TCR-T cell therapies, such as Kite Pharma, Inc., a subsidiary of Gilead, Inc., Juno Therapeutics, Inc., a subsidiary of Bristol-Myers Squibb, Inc., TCR2 Therapeutics, Inc., Poseida Therapeutics, Inc. and Immatics N.V. There are also companies utilizing other cell-based approaches that may be competitive to our product candidates. For example, companies such as Celyad, S.A., Artiva Biotherapeutics, Inc., and Nkarta, Inc. are developing therapies that target and/or engineer natural killer, or NK, cells.

Furthermore, we also face competition more broadly across the oncology market for cost-effective and reimbursable cancer treatments. The most common methods of treating patients with cancer are surgery, radiation and drug therapy, including chemotherapy, hormone therapy, biologic therapy, such as monoclonal and bispecific antibodies, immunotherapy, cell-based therapy and targeted therapy, or a combination of any such methods. There are a variety of available drug therapies marketed for cancer. In many cases, these drugs are administered in combination to enhance efficacy. While our TIL product candidates, if any are approved, may compete with these existing drugs and other therapies, to the extent they are ultimately used in combination with or as an adjunct to these therapies, our TIL therapies may not be competitive with them. Some of these drugs are branded and subject to patent protection, and others are available on a generic basis. Insurers and other third-party payors may also encourage the use of generic products or specific branded products. As a result, obtaining market acceptance of, and gaining significant share of the market for, any of our TIL therapies that we successfully introduce to the market may pose challenges. In addition, many companies are developing new oncology therapeutics, and we cannot predict what the standard of care will be as our product candidates progress through clinical development.

We could see a reduction or elimination in our commercial opportunity if our competitors develop and commercialize drugs that are safer, more effective, have fewer or less severe side effects, are more convenient to administer, are less expensive or with a more favorable label than our TIL product candidates. Our competitors also may obtain FDA or other regulatory approval for their drugs 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 TIL product candidates, if approved, are likely to be their efficacy, safety, convenience, price and the availability of reimbursement from government and other third-party payors.

Intellectual Property

Our commercial success may depend in part on our ability to obtain and maintain patent and other proprietary protection for commercially important technology, inventions, improvements and know-how related to our business; defend and enforce our patents and other intellectual property; preserve the confidentiality of our trade secrets; and operate without infringing or otherwise violating the valid enforceable patents and proprietary rights of third parties. Our ability to stop third parties from making, using, selling, offering to sell or importing our products may depend on the extent to which we have rights under valid and enforceable patents or trade secrets that cover these activities. With respect to both licensed and company-owned intellectual property, we cannot be sure that patents will be granted with respect to any of our pending patent applications or with respect to any patent applications filed by us in the future, nor can we be sure that any of our existing patents or any patents that may be granted to us in the future will be commercially useful in protecting our commercial products and methods of manufacturing the same. We may rely, in some circumstances, on trade secrets to protect our technology. However, trade secrets can be difficult to protect. See “Risk Factors – Risks Related to Our Intellectual Property.”

We actively seek to protect our proprietary technology, inventions, and other intellectual property that is commercially important to the development of our business by a variety of means, such as seeking, maintaining, and defending patent rights, whether developed internally or licensed from third parties. We also may rely on trade secrets and know-how relating to our proprietary technology platform, on continuing technological innovation and on in-licensing opportunities to develop, strengthen and maintain the strength of our position in the field of cell therapy that may be important for the development of our business. We also intend to seek patent protection or rely upon trade secret rights to protect other technologies that may be used to discover and validate targets, as well as to manufacture and develop novel cell therapy products. Additional regulatory protection may also be afforded through data exclusivity, market exclusivity and patent term extensions where available.

We are pursuing patent applications in both the US and abroad directed to our manufacturing process, including devices and methods for isolating TILs and expansion of cell populations.The earliest of these patent applications, if issued, would expire in 2038, without taking into account any possible patent term adjustment or extension.We are also pursuing patent applications in the U.S. and abroad as to indication-specific methods of treatment and our modified TIL program, including receptors providing targeted costimulation for adoptive cell therapy.

Government Regulation

The FDA and other regulatory authorities at federal, state, and local levels, as well as in foreign countries, extensively regulate, among other things, the research, development, testing, manufacture, quality control, import, export, safety, effectiveness, labeling, packaging, storage, distribution, record keeping, approval, advertising, promotion, marketing, post-approval monitoring, and post-approval reporting of biologics such as those we are developing. We, along with third-party contractors, will be required to navigate the various preclinical, clinical and commercial approval requirements of the governing regulatory agencies of the countries in which we wish to conduct studies or seek approval or licensure of our product candidates. The process of obtaining regulatory approvals and the subsequent compliance with applicable federal, state, local and foreign statutes and regulations require the expenditure of substantial time and financial resources.

U.S. Biologics Regulation

In the United States, biological products are subject to regulation under the Federal Food, Drug, and Cosmetic Act, the Public Health Service Act, and other federal, state, local and foreign statutes and regulations. The process required by the FDA before biologics may be marketed in the United States generally involves the following:

•completion of preclinical laboratory tests and animal studies performed in accordance with the FDA’s Good Laboratory Practice requirements, or GLP);

•submission to the FDA of an IND, which must become effective before clinical trials may begin;

•approval by an institutional review board, or IRB, or ethics committee at each clinical site before the trial is commenced;

•performance of adequate and well-controlled human clinical trials according to the FDA’s regulations commonly referred to as good clinical practice, or GCP, regulations and any additional requirements for the protection of human research subjects and their health information to establish the safety, purity and potency of the proposed biologic product candidate for its intended purpose;

•preparation of and submission to the FDA of a BLA, after completion of all pivotal clinical trials;

•a determination by the FDA within 60 days of its receipt of a BLA to file the application for review;

•satisfactory completion of an FDA pre-approval inspection of the manufacturing facility or facilities at which the proposed product is produced to assess compliance with current Good Manufacturing Practices, or cGMP, and to assure that the facilities, methods and controls are adequate to preserve the biological product’s continued safety, purity and potency and, if applicable, to assess compliance with the FDA’s

current Good Tissue Practice, or cGTP, requirements for the use of human cellular and tissue products, and of selected clinical investigation sites to assess compliance with Good Clinical Practices, or GCPs;

•satisfactory completion of an FDA Advisory Committee review, if applicable;

•potential FDA audit of the nonclinical and clinical study sites that generated the data in support of the BLA; and

•FDA review and approval of the BLA to permit commercial marketing of the product for particular indications for use in the United States.

Before testing any biological product candidate in humans, the product candidate enters the preclinical testing stage. Preclinical tests, also referred to as nonclinical studies, include laboratory evaluations of product chemistry, toxicity and formulation, as well as animal studies to assess the potential safety and activity of the product candidate. The conduct of the preclinical tests must comply with federal regulations and requirements including GLPs.

Prior to beginning the first clinical trial with a product candidate in the United States, we must submit an IND to the FDA. An IND is a request for authorization from the FDA to administer an investigational new drug to humans. The central focus of an IND submission is on the general investigational plan and the protocol(s) for clinical studies. The IND also includes results of animal and in vitro studies assessing the toxicology, pharmacokinetics, pharmacology, and pharmacodynamic characteristics of the product; chemistry, manufacturing, and controls information; and any available human data or literature to support the use of the investigational product. An IND must become effective before human clinical trials may begin. The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA, within the 30-day time period, raises safety concerns or questions about the proposed clinical trial. In such a case, the IND may be placed on clinical hold and the IND sponsor and the FDA must resolve any outstanding concerns or questions before the clinical trial can begin. Submission of an IND therefore may or may not result in FDA authorization to begin a clinical trial.

In addition to the submission of an IND to the FDA before initiation of a clinical trial in the United States, certain human clinical trials involving recombinant or synthetic nucleic acid molecules are subject to oversight of institutional biosafety committees, or IBCs, as set forth in the National Institutes of Health, or NIH, Guidelines for Research Involving Recombinant DNA Molecules, or the NIH Guidelines. Specifically, under the NIH Guidelines, supervision of human gene transfer trials includes evaluation and assessment by an IBC, a local institutional committee that reviews and oversees research utilizing recombinant or synthetic nucleic acid molecules at that institution. The IBC assesses the safety of the research and identifies any potential risk to public health or the environment, and such review may result in some delay before initiation of a clinical trial. While the NIH Guidelines are not mandatory unless the research in question is being conducted at or sponsored by institutions receiving NIH funding of recombinant or synthetic nucleic acid molecule research, many companies and other institutions not otherwise subject to the NIH Guidelines voluntarily follow them.

Clinical trials involve the administration of the investigational product to human subjects under the supervision of qualified investigators in accordance with GCPs, which include the requirement that all research subjects provide their informed consent for their participation in any clinical study. Clinical trials are conducted under protocols detailing, among other things, the objectives of the study, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated. A separate submission to the existing IND must be made for each successive clinical trial conducted during product development and for any subsequent protocol amendments. Furthermore, an independent IRB for each site proposing to conduct the clinical trial must review and approve the plan for any clinical trial and its informed consent form before the clinical trial begins at that site, and must monitor the study until completed. Regulatory authorities, the IRB or the sponsor may suspend a clinical trial at any time on various grounds, including a finding that the subjects are being exposed to an unacceptable health risk or that the trial is unlikely to meet its stated objectives. Some studies also include oversight by an independent group of qualified experts organized by the clinical study sponsor, known as a data safety monitoring board, which provides authorization for whether or not a study may move forward at designated check points based on access to certain data from the study and may halt the clinical trial if it determines that there is an unacceptable safety risk for subjects

or other grounds, such as no demonstration of efficacy. There are also requirements governing the reporting of ongoing clinical studies and clinical study results to public registries.

For purposes of BLA approval, human clinical trials are typically conducted in three sequential phases that may overlap or be combined:

•Phase 1—The investigational product is initially introduced into healthy human subjects or patients with the target disease or condition. These studies are designed to test the safety, dosage tolerance, absorption, metabolism and distribution of the investigational product in humans, the side effects associated with increasing doses, and, if possible, to gain early evidence on effectiveness.

•Phase 2—The investigational product is administered to a limited patient population with a specified disease or condition to evaluate the preliminary efficacy, optimal dosages and dosing schedule and to identify possible adverse side effects and safety risks. Multiple Phase 2 clinical trials may be conducted to obtain information prior to beginning larger and more expensive Phase 3 clinical trials.

•Phase 3—The investigational product is administered to an expanded patient population to further evaluate dosage, to provide statistically significant evidence of clinical efficacy and to further test for safety, generally at multiple geographically dispersed clinical trial sites. These clinical trials are intended to establish the overall risk/benefit ratio of the investigational product and to provide an adequate basis for product approval.

In some cases, the FDA may require, or companies may voluntarily pursue, additional clinical trials after a product is approved to gain more information about the product in the intended therapeutic indication, particularly for long-term safety follow-up. These so-called Phase 4 studies may also be made a condition to approval of the BLA.

Concurrent with clinical trials, companies may complete additional animal studies and develop additional information about the biological characteristics of the product candidate, and must 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 candidate and, among other things, 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.

BLA Submission and Review by the FDA

Assuming successful completion of all required testing in accordance with all applicable regulatory requirements, the results of product development, nonclinical studies and clinical trials are submitted to the FDA as part of a BLA requesting approval to market the product for one or more indications. The BLA must include all relevant data available from preclinical and clinical studies, including negative or ambiguous results as well as positive findings, together with detailed information relating to the product’s chemistry, manufacturing, controls, and proposed labeling, among other things. Data can come from company-sponsored clinical studies intended to test the safety and effectiveness of a use of the product, or from a number of alternative sources, including studies initiated by independent investigators. The submission of a BLA requires payment of a substantial application user fee to the FDA, unless a waiver or exemption applies.

Within 60 days following submission of the application, the FDA reviews a BLA submitted to determine if it is substantially complete before the FDA accepts it for filing. The FDA may refuse to file any BLA that it deems incomplete or not properly reviewable at the time of submission and may request additional information. In this event, the BLA must be resubmitted with the additional information. Once a BLA has been accepted for filing, the FDA’s goal is to review standard applications within ten months after the filing date, or, if the application qualifies

for priority review, six months after the FDA accepts the application for filing. In both standard and priority reviews, the review process may also be extended by FDA requests for additional information or clarification. The FDA reviews a BLA to determine, among other things, whether a product is safe, pure and potent and the facility in which it is manufactured, processed, packed or held meets standards designed to assure the product’s continued safety, purity and potency. The FDA may also convene an advisory committee to provide clinical insight on application review questions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions.

Before approving a BLA, the FDA will typically inspect the facility or facilities where the product is manufactured. The FDA will not approve an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP and adequate to assure consistent production of the product within required specifications. For a product candidate that is also a human cellular or tissue product, the FDA also will not approve the application if the manufacturer is not in compliance with cGTPs. These are FDA regulations that govern the methods used in, and the facilities and controls used for, the manufacture of human cells, tissues, and cellular and tissue based products, or HCT/Ps, which are human cells or tissue intended for implantation, transplant, infusion, or transfer into a human recipient. The primary intent of the GTP requirements is to ensure that cell and tissue based products are manufactured in a manner designed to prevent the introduction, transmission and spread of communicable disease. FDA regulations also require tissue establishments to register and list their HCT/Ps with the FDA and, when applicable, to evaluate donors through screening and testing. Additionally, before approving a BLA, the FDA will typically inspect one or more clinical sites to assure compliance with GCP. If the FDA determines that the application, manufacturing process or manufacturing facilities are not acceptable, it will outline the deficiencies in the submission and often will request additional testing or information. Notwithstanding the submission of any requested additional information, the FDA ultimately may decide that the application does not satisfy the regulatory criteria for approval.

After the FDA evaluates a BLA and conducts inspections of manufacturing facilities where the investigational product and/or its drug substance will be produced, the FDA may issue an approval letter or a Complete Response Letter, or CRL. An approval letter authorizes commercial marketing of the product with specific prescribing information for specific indications. A CRL will describe all of the deficiencies that the FDA has identified in the BLA, except that where the FDA determines that the data supporting the application are inadequate to support approval, the FDA may issue the CRL without first conducting required inspections, testing submitted product lots, and/or reviewing proposed labeling. In issuing the CRL, the FDA may recommend actions that the applicant might take to place the BLA in condition for approval, including requests for additional information or clarification. The FDA may delay or refuse approval of a BLA if applicable regulatory criteria are not satisfied, require additional testing or information and/or require post-marketing testing and surveillance to monitor safety or efficacy of a product.

If regulatory approval of a product is granted, such approval will be granted for particular indications and may entail limitations on the indicated uses for which such product may be marketed. For example, the FDA may approve the BLA with a Risk Evaluation and Mitigation Strategy, or REMS, to ensure the benefits of the product outweigh its risks, or otherwise limit the scope of any approval. A REMS is a safety strategy implemented to manage a known or potential serious risk associated with a product and to enable patients to have continued access to such medicines by managing their safe use, and 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. The FDA also may condition approval on, among other things, changes to proposed labeling or the development of adequate controls and specifications. Once approved, the FDA may withdraw the product approval if compliance with pre- and post-marketing requirements is not maintained or if problems occur after the product reaches the marketplace. The FDA may require one or more Phase 4 post-market studies and surveillance to further assess and monitor the product’s safety and effectiveness after commercialization, and may limit further marketing of the product based on the results of these post-marketing studies.

Expedited Development and Review Programs

The FDA offers a number of expedited development and review programs for qualifying product candidates. For example, the Fast Track program is intended to expedite or facilitate the process for reviewing new products that are intended to treat a serious or life-threatening disease or condition and demonstrate the potential to address unmet medical needs for the disease or condition. Specifically, new biological products are eligible for Fast Track designation if they are intended to treat a serious or life-threatening disease or condition and demonstrate the potential to address unmet medical needs for the disease or condition. Fast Track designation applies to the combination of the product and the specific indication for which it is being studied. The sponsor of a new biologic may request that the FDA designate the biologic as a Fast Track product at any time during the clinical development of the product. The sponsor of a Fast Track product has opportunities for more frequent interactions with the applicable FDA review team during product development and, once a BLA is submitted, the product candidate may be eligible for priority review. A Fast Track product may also be eligible for rolling review, where the FDA may consider for review sections of the BLA on a rolling basis before the complete application is submitted, if the sponsor provides a schedule for the submission of the sections of the BLA, the FDA agrees to accept sections of the BLA and determines that the schedule is acceptable, and the sponsor pays any required user fees upon submission of the first section of the BLA.

A product candidate intended to treat a serious or life-threatening disease or condition may also be eligible for breakthrough therapy designation to expedite its development and review. A product candidate can receive breakthrough therapy designation if preliminary clinical evidence indicates that the product candidate, alone or in combination with one or more other drugs or biologics, may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. The designation includes all of the Fast Track program features, as well as more intensive FDA interaction and guidance beginning as early as Phase 1 and an organizational commitment to expedite the development and review of the product candidate, including involvement of senior managers.

Any marketing application for a drug or biologic submitted to the FDA for approval, including a product candidate with a Fast Track designation and/or breakthrough therapy designation, may be eligible for other types of FDA programs intended to expedite development and review, such as priority review and accelerated approval. A product candidate is eligible for priority review if it has the potential to provide safe and effective therapy where no satisfactory alternative therapy exists or a significant improvement in the treatment, diagnosis or prevention of a disease compared to marketed products.. The FDA will attempt to direct additional resources to the evaluation of an application for a new biological product designated for priority review in an effort to facilitate the review. For original BLAs, priority review designation means the FDA’s goal is to take action on the marketing application within six months of the 60-day filing date (as compared to ten months under standard review).

Additionally, product candidates studied for their safety and effectiveness in treating serious or life-threatening diseases or conditions may receive accelerated approval upon a determination that the product has an effect on 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, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments. As a condition of accelerated approval, the FDA will generally require the sponsor to perform adequate and well-controlled post-marketing clinical studies to verify and describe the anticipated effect on irreversible morbidity or mortality or other clinical benefit. Products receiving accelerated approval may be subject to expedited withdrawal procedures if the sponsor fails to conduct the required post-marketing studies or if such studies fail to verify the predicted clinical benefit. In addition, the FDA currently requires as a condition for accelerated approval pre-approval of promotional materials, which could adversely impact the timing of the commercial launch of the product.

Regenerative medicine advanced therapy, or RMAT, designation, is intended to facilitate an efficient development program for, and expedite review of, any drug or biologic that meets the following criteria: (i) the drug or biologic qualifies as a RMAT, which is defined as a cell therapy, therapeutic tissue engineering product, human cell and tissue product, or any combination product using such therapies or products, with limited exceptions; (ii) the drug or biologic is intended to treat, modify, reverse, or cure a serious or life-threatening disease or condition; and

(iii) preliminary clinical evidence indicates that the drug or biologic has the potential to address unmet medical needs for such a disease or condition. RMAT designation provides all the benefits of breakthrough therapy designation, including more frequent meetings with the FDA to discuss the development plan for the product candidate and eligibility for rolling review and priority review. Product candidates granted RMAT designation may also be eligible for accelerated approval on the basis of a surrogate or intermediate endpoint reasonably likely to predict long-term clinical benefit, or reliance upon data obtained from a meaningful number of clinical trial sites, including through expansion of trials to additional sites. RMAT-designated products that receive accelerated approval may, as appropriate, fulfill their post-approval requirements through submission of clinical evidence, clinical studies, patient registries, or other sources of real-world evidence (such as electronic health records); through the collection of larger confirmatory data sets; or via post-approval monitoring of all patients treated with such therapy prior to approval of such therapy.

Fast Track designation, breakthrough therapy designation, priority review, accelerated approval, and RMAT designation do not change the standards for approval but may expedite the development or approval process. Even if a product candidate qualifies for one or more of these programs, the FDA may later decide that the product no longer meets the conditions for qualification or decide that the time period for FDA review or approval will not be shortened.

Orphan Drug Designation and Exclusivity

Under the Orphan Drug Act, the FDA may grant orphan designation to a drug or biologic intended to treat a rare disease or condition, defined as a disease or condition with a patient population of fewer than 200,000 individuals in the United States, or a patient population greater than 200,000 individuals in the United States and when there is no reasonable expectation that the cost of developing and making available the drug or biologic in the United States will be recovered from sales in the United States for that drug or biologic. Orphan drug designation must be requested before submitting a BLA. After the FDA grants orphan drug designation, the generic 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.

In the United States, orphan drug designation entitles a party to financial incentives such as opportunities for grant funding towards clinical trial costs, tax advantages and user-fee waivers. In addition, if a product that has orphan drug designation subsequently receives the first FDA approval for a particular drug or biologic for the disease 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, including a full BLA, to market the same biologic for the same indication for seven years, except in limited circumstances, such as a showing of clinical superiority to the product with orphan drug exclusivity or if the FDA finds that the holder of the orphan drug exclusivity has not shown that it can assure the availability of sufficient quantities of the orphan drug to meet the needs of patients with the disease or condition for which the drug was designated. Orphan drug exclusivity does not prevent the FDA from approving a different drug or biologic for the same disease or condition, or the same drug or biologic for a different disease or condition. Orphan product exclusivity also could block the approval of one of our products for seven years if a competitor obtains approval of the same biological product as defined by the FDA or if our product candidate is determined to be contained within the competitor’s product for the same indication or disease.

A designated orphan drug may not receive orphan drug exclusivity if it is approved for a use that is broader than the indication for which it received orphan designation. In addition, orphan drug exclusive marketing rights in the United States may be lost if the FDA later determines that the request for designation was materially defective or, as noted above, if a second applicant demonstrates that its product is clinically superior to the approved product with orphan exclusivity or the manufacturer of the approved product is unable to assure sufficient quantities of the product to meet the needs of patients with the rare disease or condition.

Post-Approval Requirements

Biologics are subject to pervasive and continuing regulation by the FDA, including, among other things, requirements relating to record-keeping, reporting of adverse experiences, periodic reporting, product sampling and distribution, and advertising and promotion of the product. After approval, most changes to the approved product, such as adding new indications or other labeling claims, are subject to prior FDA review and approval. There also are continuing, annual program fees for any marketed products. Biologic manufacturers and other entities involved in the manufacture and distribution of approved biological products 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 GMP compliance. Changes to the manufacturing process or facility are strictly regulated, and, depending on the significance of the change, may require prior FDA approval before being implemented. FDA regulations also require investigation and correction of any deviations from cGMP and impose reporting requirements. Accordingly, manufacturers must continue to expend time, money and effort in the area of production and quality control to maintain compliance with cGMP and other aspects of regulatory compliance.

The FDA may withdraw approval if compliance with regulatory requirements and standards is not maintained or if problems occur after the product reaches the market. Later discovery of previously unknown problems with a product, including adverse events of unanticipated severity or frequency, or with manufacturing processes, or failure to comply with regulatory requirements, may result in revisions to the approved labeling to add new safety information; imposition of post-market studies or clinical studies to assess new safety risks; or imposition of distribution restrictions or other restrictions under a REMS program. Other potential consequences include, among other things:

•restrictions on the marketing or manufacturing of the product, complete withdrawal of the product from the market or product recalls;

•fines, warning letters, or untitled letters;

•clinical holds on clinical studies;

•refusal of the FDA to approve pending applications or supplements to approved applications, or suspension or revocation of product license approvals;

•product seizure or detention, or refusal to permit the import or export of products;

•consent decrees, corporate integrity agreements, debarment or exclusion from federal healthcare programs;

•mandated modification of promotional materials and labeling and the issuance of corrective information;

•the issuance of safety alerts, Dear Healthcare Provider letters, press releases and other communications containing warnings or other safety information about the product; or

•injunctions or the imposition of civil or criminal penalties.

The FDA closely regulates the marketing, labeling, advertising and promotion of biologics. A company can make only those claims relating to safety and efficacy, purity and potency that are approved by the FDA and in accordance with the provisions of the approved label. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses. Failure to comply with these requirements can result in, among other things, adverse publicity, warning letters, corrective advertising and potential civil and criminal penalties. FDA sanctions could include refusal to approve pending applications, withdrawal of an approval, clinical hold, warning or untitled letters, product recalls, product seizures, 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, or civil or criminal penalties. Physicians may prescribe legally available products for uses that are not described in the product’s labeling and that differ from those tested and approved by the FDA. Such off-label uses are common across medical specialties. Physicians may believe that such off-label uses are the best treatment for many patients in varied circumstances. The FDA does not regulate the behavior of physicians in their choice of treatments. The FDA does, however, restrict manufacturer’s communications on the subject of off-label use of their products.

Government Regulation Outside of the United States

In addition to regulations in the United States, we will be subject to a variety of regulations in other jurisdictions governing, among other things, clinical studies and any commercial sales and distribution of our products. Because biologically sourced raw materials are subject to unique contamination risks, their use may be restricted in some countries. Whether or not we obtain FDA approval for a product, we must obtain the requisite approvals from regulatory authorities in foreign countries prior to the commencement of clinical studies or marketing of the product in those countries. Certain countries outside of the United States have a similar process that requires the submission of a clinical study application much like the IND prior to the commencement of human clinical studies.

In the European Union, for example, a clinical trial application, or CTA, must be submitted to each country’s national health authority and an independent ethics committee, much like the FDA and the IRB, respectively. Once the CTA is approved in accordance with the applicable requirements, clinical study development may proceed. The requirements and process governing the conduct of clinical studies, are to a significant extent harmonized at the European Union-level but could vary from country to country. In all cases, the clinical studies are conducted in accordance with Good Clinical Practices, or GCP, and the applicable regulatory requirements and the ethical principles that have their origin in the Declaration of Helsinki. The way clinical trials are conducted in the European Union will undergo a major change when the Clinical Trial Regulation (Regulation (EU) No 536/2014) comes into application, probably in 2022. The Regulation harmonizes the assessment and supervision processes for clinical trials throughout the European Union via a Clinical Trials Information System, which will contain a centralized European Union portal and database.

To obtain regulatory approval of an investigational biological product under European Union regulatory systems, we must submit a marketing authorization application. The application used to file the BLA in the United States is similar to that required in the European Union, with the exception of, among other things, country-specific document requirements. Innovative products that target an unmet medical need may be eligible for a number of expedited development and review programs in the European Union, such as the PRIME scheme, which provides incentives similar to the breakthrough therapy designation in the United States. Such products are generally eligible for accelerated assessment and may also benefit from different types of Fast Track approvals, such as a conditional marketing authorization or a marketing authorization under exceptional circumstances granted on the basis of less comprehensive clinical data than normally required (respectively in the likelihood that the sponsor will provide such data within an agreed timeframe or when comprehensive data cannot be obtained even after authorization).

The European Union also provides opportunities for market exclusivity. For example, in the European Union, upon receiving marketing authorization, new chemical entities generally receive eight years of data exclusivity and an additional two years of market exclusivity. If granted, data exclusivity prevents regulatory authorities in the European Union from referencing the innovator’s data to assess a generic or biosimilar application. During the additional two-year period of market exclusivity, a generic or biosimilar marketing authorization can be submitted, and the innovator’s data may be referenced, but no generic or biosimilar product can be marketed until the expiration of the market exclusivity. However, there is no guarantee that a product will be considered by the European Union’s regulatory authorities to be a new chemical entity, and products may not qualify for data exclusivity. Products receiving orphan designation in the European Union can receive ten years of market exclusivity, during which time no similar medicinal product for the same indication may be placed on the market. An orphan product can also obtain an additional two years of market exclusivity in the European Union for pediatric studies. No extension to any supplementary protection certificate can be granted on the basis of pediatric studies for orphan indications.

The criteria for designating an “orphan medicinal product” in the European Union are similar in principle to those in the United States. Under Article 3 of Regulation (EC) 141/2000, a medicinal product may be designated as orphan if (1) it is intended for the diagnosis, prevention or treatment of a life-threatening or chronically debilitating condition; (2) either (a) such condition affects no more than five in 10,000 persons in the European Union when the application is made, or (b) the product, without the benefits derived from orphan status, would not generate

sufficient return in the European Union to justify investment; and (3) there exists no satisfactory method of diagnosis, prevention or treatment of such condition authorized for marketing in the European Union, or if such a method exists, the product will be of significant benefit to those affected by the condition, as defined in Regulation (EC) 847/2000. Orphan medicinal products are eligible for financial incentives such as reduction of fees or fee waivers and are, upon grant of a marketing authorization, entitled to ten years of market exclusivity for the approved therapeutic indication. The application for orphan drug designation must be submitted before the application for marketing authorization. The applicant will receive a fee reduction for the marketing authorization application if the orphan drug designation has been granted, but not if the designation is still pending at the time the marketing authorization is submitted. Orphan drug designation does not convey any advantage in, or shorten the duration of, the regulatory review and approval process.

The 10-year market exclusivity may be reduced to six years if, at the end of the fifth year, it is established that the product no longer meets the criteria for orphan designation, for example, if the product is sufficiently profitable not to justify maintenance of market exclusivity. Additionally, marketing authorization may be granted to a similar product for the same indication at any time if:

•The second applicant can establish that its product, although similar, is safer, more effective or otherwise clinically superior;

•The applicant consents to a second orphan medicinal product application; or

•The applicant cannot supply enough orphan medicinal product.

The medicinal products we are developing, which are based on genes, cells or tissues, may be considered advanced therapy medicinal products, or ATMPs, in the European Union if they meet the scientific criteria for defining an ATMP. The principles of the aforementioned medicines legislation apply to ATMPs. All ATMPs must obtain a marketing authorization from the EMA and are regulated through the centralized authorization procedure. Regulation (EC) No 1394/2007, or the ATMP Regulation, provides specific incentives to accelerate the development of such products, including fee reductions for scientific advice, an ATMP classification procedure (for all developers) and a certification procedure for quality and non-clinical data (for SMEs only).

If tissues and cells are being used as starting materials in a medicinal product we may also need to comply with the requirements of Directive 2004/23/EC, or the European Tissues and Cells Directive, covering standards for donation, procurement and testing, processing, preservation, storage and distribution of human tissues and cells, as well as its technical implementing directives; and Directive 2015/566, as regards the procedures for verifying the equivalent standards of quality and safety of imported tissues and cells.

In the European Union, early access mechanisms for innovative medicines (such as compassionate use programs and named patient supplies), pricing and reimbursement, and promotion and advertising are subject to national regulations and oversight by national competent authorities and therefore significantly vary from country to country.

Sanctions for non-compliance with the aforementioned requirements, which may include administrative and criminal penalties, are generally determined and enforced at national level. However, under the European Union financial penalties regime, the EMA can investigate and report on alleged breaches of the European Union pharmaceutical rules by holders of a marketing authorization for centrally authorized medicinal products and the European Commission could adopt decisions imposing significant financial penalties on infringing marketing authorization holders.

The United Kingdom has left the European Union on January 31, 2020. Following the Transition Period which ended on December 31, 2020, Brexit could materially impact the regulatory regime with respect to the development, manufacture, importation, approval and commercialization of our product candidates in the United Kingdom in the coming years.

For other countries outside of the European Union, such as countries in Eastern Europe, Latin America or Asia, the requirements governing the conduct of clinical studies, product licensing, pricing and reimbursement vary from country to country. In all cases, again, the clinical studies are conducted in accordance with GCP and the applicable regulatory requirements and the ethical principles that have their origin in the Declaration of Helsinki.

If we fail to comply with applicable foreign 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.

Other Healthcare Laws

Pharmaceutical companies are subject to additional healthcare regulation and enforcement by the federal government and by authorities in the states and foreign jurisdictions in which they conduct their business and may constrain the financial arrangements and relationships through which we research, as well as, sell, market and distribute any products for which we obtain marketing approval. Such laws include, without limitation, federal and state anti-kickback, fraud and abuse, false claims, data privacy and security and physician and other health care provider transparency laws and regulations. The laws that will affect our operations include, but are not limited to:

•the federal Anti-Kickback Statute , which prohibits, among other things, persons from knowingly and willfully soliciting, offering, receiving or providing remuneration (including any kickback, bribe or rebate), directly or indirectly, in cash or in kind, to induce or reward either the referral of an individual for, or the purchase, order or recommendation of, any good or service for which payment may be made under federal and state healthcare programs such as Medicare and Medicaid;

•federal civil and criminal false claims laws and civil monetary penalty laws, including the federal False Claims Act, impose criminal or civil penalties, as applicable, against individuals or entities for knowingly presenting, or causing to be presented, to the federal government (including the Medicare and Medicaid programs) or other third-party payor claims for payment that are false or fraudulent or making a false statement to avoid, decrease or conceal an obligation to pay money to the federal government;

•Health Insurance Portability and Accountability Act of 1996, or HIPAA established the federal offense of health care fraud, which among other things, imposes criminal liability for knowingly and willfully executing, or attempting to execute, a scheme to defraud any healthcare benefit program or to obtain, by means of false or fraudulent pretenses, representations, or promises, any of the money or property owned by, or under the custody or control of, any healthcare benefit program, regardless of the payor (e.g. public or private) and knowingly and willfully falsifying, concealing or covering up by any trick or device a material fact or making any materially false statements in connection with the delivery of or payment for healthcare benefits, items or services relating to healthcare matters;

•HIPAA, as amended byHealth Information Technology for Economic and Clinical Health Act , orHITECH, and its implementing regulations, which imposes certain obligations, including mandatory contractual terms, with respect to safeguarding the privacy, security and transmission of individually identifiable health information without the appropriate authorization by entities subject to the law, such as health plans, healthcare clearinghouses and healthcare providers and their respective business associates and their covered subcontractors;

•the federal the Physician Payments Sunshine Act and its implementing regulations, requires applicable group purchasing organizations and manufacturers of drugs, devices, biologics and medical supplies for which payment is available under Medicare, Medicaid or the Children’s Health Insurance Program (with certain exceptions) to report annually to HHS information related to “payments or other transfers of value” made in the previous year to covered recipients, including physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors, other health care professionals (such asnurse practitioners and physician assistants) and teaching hospitals, and information regarding ownership and investment interests held by physicians (as defined above) or their immediate family members; and

•analogous state and foreign laws and regulations, including: state anti-kickback and false claims laws that may apply to our business practices (including research, distribution, sales and marketing arrangements and claims involving healthcare items or services reimbursed by state governmental and non-governmental third-party payors, including private insurers); state laws that require pharmaceutical companies to comply with the pharmaceutical industry’s voluntary compliance guidelines and the applicable compliance guidance promulgated by the federal government; state laws that require drug manufacturers to track gifts and other remuneration and items of value provided to healthcare professionals and entities and file reports relating to pricing and marketing information; and state and foreign laws that govern the privacy and security of health information in specified circumstances, many of which differ from each other in significant ways and often are not preempted by HIPAA, thus complicating compliance efforts.

Because of the breadth of these laws and the narrowness of any available statutory exceptions and safe harbors, it is possible that some of our current and future business activities could be subject to challenge under one or more of such laws.

If our significant operations are found to be in violation of any of such laws or any other governmental regulations that apply, they may be subject to penalties, including, without limitation, administrative, civil and criminal penalties, damages, fines, disgorgement, the curtailment or restructuring of operations, integrity oversight and reporting obligations, exclusion from participation in federal and state healthcare programs and imprisonment.

Coverage and Reimbursement

Sales of any product depend, in part, on the extent to which such product will be covered by third-party payors, such as federal, state, and foreign government healthcare programs, commercial insurance and managed healthcare organizations, and the level of reimbursement for such product by third-party payors. Decisions regarding the extent of coverage and amount of reimbursement to be provided are made on a plan-by-plan basis. These third-party payors are increasingly reducing coverage and reimbursement for medical products, drugs and services. In addition, the U.S. government, state legislatures and foreign governments have continued implementing cost-containment programs, including price controls, restrictions on coverage and reimbursement and requirements for substitution of generic products. Adoption of price controls and cost-containment measures, and adoption of more restrictive policies in jurisdictions with existing controls and measures, could further limit sales of any product. Decreases in third-party reimbursement for any product or a decision by a third-party payor not to cover a product could reduce physician usage and patient demand for the product and also have a material adverse effect on sales.

Healthcare Reform

In the United States, in March 2010, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act, each as amended, collectively known as the ACA, was enacted, which substantially changed the way healthcare is financed by both governmental and private insurers, and significantly affected the pharmaceutical industry. The ACA contained a number of provisions, including those governing enrollment in federal healthcare programs, reimbursement adjustments and changes to fraud and abuse laws. For example, the ACA:

•increased the minimum level of Medicaid rebates payable by manufacturers of brand name drugs from 15.1% to 23.1% of the average manufacturer price;

•required collection of rebates for drugs paid by Medicaid managed care organizations;

•required manufacturers to participate in a coverage gap discount program, under which they must agree to offer 70 percent point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during their coverage gap period, as a condition for the manufacturer’s outpatient drugs to be covered under Medicare Part D; and

•imposed a non-deductible annual fee on pharmaceutical manufacturers or importers who sell “branded prescription drugs” to specified federal government programs.

Since its enactment, there have been judicial and Congressional challenges to certain aspects of the ACA. For example, on June 17, 2021, the U.S. Supreme Court dismissed the most recent judicial challenge to the ACA brought by several states without specifically ruling on the constitutionality of the ACA. Prior to the Supreme Court’s decision, President Biden issued an executive order that initiated a special enrollment period for purposes of obtaining health insurance coverage through the ACA marketplace. The executive order also instructed certain governmental agencies to review and reconsider their existing policies and rules that limit access to healthcare, including among others, reexamining Medicaid demonstration projects and waiver programs that include work requirements, and policies that create unnecessary barriers to obtaining access to health insurance coverage through Medicaid or the ACA. Other legislative changes have been proposed and adopted since the ACA was enacted, including aggregate reductions of Medicare payments to providers of 2% per fiscal year, which was temporarily suspended from May 1, 2020 through March 31, 2022 due to the COVID-19 pandemic, and reduced payments to several types of Medicare providers. Under current legislation the actual reduction in Medicare payments will vary from 1% in 2022 to up to 3% in the final fiscal year of this sequester. Additionally, on March 11, 2021, President Biden signed the American Rescue Plan Act of 2021 into law, which eliminates the statutory Medicaid drug rebate cap, currently set at 100% of a drug’s average manufacturer price, for single source and innovator multiple source drugs, beginning January 1, 2024. Moreover, there has recently been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed products, which has resulted in several Congressional inquiries, proposed and enacted legislation and executive orders issued by the President designed to, among other things, bring more transparency to product pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drug products. It is also possible that additional governmental action is taken in response to the COVID-19 pandemic. In July 2021, the Biden administration released an executive order, “Promoting Competition in the American Economy,” with multiple provisions aimed at prescription drugs. In response to Biden’s executive order, on September 9, 2021, HHS released a Comprehensive Plan for Addressing High Drug Prices that outlines principles for drug pricing reform and sets out a variety of potential legislative policies that Congress could pursue to advance these principles. No legislation or administrative actions have been finalized to implement these principles. In addition, Congress is considering drug pricing as part of other reform initiatives. Similar reform measures are been considered and adopted at the state level as well.

Individual states in the United States have also become increasingly active in implementing regulations designed to control pharmaceutical 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, designed to encourage importation from other countries and bulk purchasing.

Facilities

We control and operate our manufacturing site in Manchester, United Kingdom, which consists of 12,957 total square feet of leased laboratory and office space undereight leases that expire in July 2022, January 2023, and July 2024. We own and are developing our manufacturing facility in Tarzana, California, which has 102,607 square feet of clinical and manufacturing space, and lease 6,000 square feet of office space in Tarzana, California. Our Tarzana clinical manufacturing facility is expected to become operational in the first half of 2022.

Our headquarters is currently located in Dallas, Texas and consists of 5,055 square feet of leased office space under a lease that expires in April 2026. We also lease 42,240 square feet of laboratory and office space in Thousand Oaks, California, under a lease that expires in October 2026, and 7,036 square feet of leased laboratory and office space in Alderley Park, United Kingdom, under two leases that expire in November 2025 and April 2026, which in each case is subject to renewal. Additionally, we lease laboratory and office space in other parts of the United States. We believe that our facilities are adequate for our current needs, and that suitable additional alternative spaces will be available in the future on commercially reasonable terms.

Employees and Human Capital Resources

As of December 31, 2021, we had 412 full-time employees. Of these employees, 352 were engaged in research and development activities and 68 held Ph.D. or M.D. degree. Substantially all of our employees are based in Dallas, Texas, greater Los Angeles, California and Manchester, United Kingdom. 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.

Our human capital resources objectives include, as applicable, identifying, recruiting, retaining, incentivizing and integrating our existing and new employees, advisors and consultants. The principal purposes of our equity and cash incentive plans are to attract, retain and reward personnel through the granting of stock-based and cash-based compensation awards, in order to increase stockholder value and the success of our company by motivating such individuals to perform to the best of their abilities and achieve our objectives.

Legal Proceedings

From time to time, we may become involved in legal proceedings arising in the ordinary course of our business. We are not currently subject to any material legal proceedings.

Corporate Information

We were incorporated under the laws of the State of Delaware in August of 2018. Our principal executive offices are located at 3963 Maple Avenue, Suite 350, Dallas, Texas 75219and our telephone number is (972) 499-3350. Our website address is instilbio.com. The information contained on, or accessible through, our website is not incorporated by reference into this prospectus, and you should not consider any information contained in, or that can be accessed through, our website as part of this prospectus or in deciding whether to purchase our common stock. We have included our website in this prospectus solely as an inactive textual reference.

Available Information

Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and amendments to reports filed pursuant to Sections 13(a) and 15(d) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, will be made available free of charge on our website as soon as reasonably practicable after we electronically file such material with, or furnish it to, the Securities and Exchange Commission, or SEC. The contents of our website are not incorporated into this Annual Report and our reference to the URL for our website is intended to be an inactive textual reference only. The information contained on, or that can be accessed through, our website is not a part of this document.

Item 1A. Risk Factors.

RISK FACTORS

The following information sets forth risk factors that could cause our actual results to differ materially from those contained in forward-looking statements we have made in this Annual Report on Form 10-K and those we may make from time to time. You should carefully consider the risks described below, in addition to the other information contained in this Annual Report on Form 10-K and our other public filings. Our business, financial condition or results of operations could be harmed by any of these risks. The risks and uncertainties described below are not the only ones we face. Additional risks not presently known to us or other factors not perceived by us to present significant risks to our business at this time also may impair our business operations.

Risks Associated with Our Business

Our business is subject to a number of risks of which you should be aware before making a decision to invest in our common stock. These risks are more fully described in this “Risk Factors” section, including the following:

•We have incurred significant losses since our inception. We expect to incur losses over the next several years and may never achieve or maintain profitability.

•We have a limited operating history and no history of commercializing products, which may make it difficult for an investor to evaluate the success of our business to date and to assess our future viability.

•We will need substantial additional funding to meet our financial obligations and to pursue our business objectives. If we are unable to raise capital when needed, we could be forced to curtail our planned operations and the pursuit of our growth strategy.

•All of our product candidates are currently in clinical and preclinical development. If we are unable to successfully develop, receive regulatory approval for and commercialize our product candidates for the indications we seek, or successfully develop any other product candidates, or experience significant delays in doing so, our business will be harmed.

•Because ITIL-168, as well as ITIL-306 and any future product candidates developed from our CoStAR platform, represent novel approaches to the treatment of disease, there are many uncertainties regarding the development, market acceptance, third-party reimbursement coverage and commercial potential of our product candidates.

•The regulatory approval processes of the FDA, EMA and comparable foreign authorities are lengthy, time consuming and inherently unpredictable. If we are not able to obtain required regulatory approval for our product candidates, our business will be substantially harmed.

•Success in preclinical studies or earlier clinical trials, including our compassionate use program, may not be indicative of results in future clinical trials. Our product candidates may not have favorable results in later clinical trials, if any, or receive regulatory approval.

•Negative public opinion of TIL therapies and increased regulatory scrutiny of cell therapy using TILs may adversely impact the development or commercial success of our current and future product candidates.

•As an organization, we are early in the process of conducting our first clinical trial, have no prior experience in conducting clinical trials, and may be unable to do so for any product candidates we may develop, including ITIL-168. Further, the FDA, EMA or other foreign regulatory authorities may require us to obtain and submit additional nonclinical data supporting the comparability of ITIL-168 with the TIL product that was evaluated in the compassionate use program in the United Kingdom that was manufactured using a prior version of the ITIL-168 manufacturing process, or may not permit us to rely on the data from the compassionate use program to support the development of ITIL-168 at all, which could delay clinical development or marketing approval of ITIL-168

•We may not be successful in our efforts to build a pipeline of additional product candidates.

•Our business and operations may be adversely affected by the evolving and ongoing COVID-19 global pandemic.

•Cell therapies are complex and difficult to manufacture. We could experience manufacturing problems that result in delays in the development or commercialization of our product candidates or otherwise harm our business.

•The affected populations for our product candidates may be smaller than we or third parties currently project, which may affect the addressable markets for our product candidates.

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

•If we are unable to obtain or protect intellectual property rights related to any of our product candidates, we may not be able to compete effectively in our market.

•Third parties may initiate legal proceedings alleging that we are infringing their intellectual property rights, the outcome of which would be uncertain.

Risks Related to our Financial Position and Capital Needs

We have incurred significant losses since our inception. We expect to incur losses over the next several years and may never achieve or maintain profitability.

Since our inception, we have incurred significant net losses, and we expect to continue to incur significant expenses and operating losses for the foreseeable future. Our net losses were $156.8 million and $37.7 million for the years ended December 31, 2021 and 2020, respectively. As of December 31, 2021, we had an accumulated deficit of $201.7 million. Since 2019, we have financed our operations with $719.0 million in net proceeds raised in our initial public offering and private placements of convertible preferred stock to date. We have no products approved for commercialization and have never generated any revenue from product sales.

All of our product candidates are still in clinical and preclinical testing. We expect to continue to incur significant expenses and operating losses over the next several years. We expect that it could be several years, if ever, before we have a commercialized product. Our net losses may fluctuate significantly from quarter to quarter and year to year. We anticipate that our expenses will increase substantially as we:

•conduct our ongoing clinical trial of ITIL-168 and planned clinical trial of ITIL-306, as well as initiate and complete additional clinical trials of future product candidates or current product candidates in new indications;

•continue to advance the preclinical and clinical development of our product candidates and our preclinical and discovery programs, including in our CoStAR platform;

•seek regulatory approval for any product candidates that successfully complete clinical trials;

•continue to develop our product candidate pipeline;

•scale up our clinical and regulatory capabilities;

•manufacture current good manufacturing practices, or cGMP, material for clinical trials or potential commercial sales at our manufacturing facilities;

•establish and validate a commercial-scale cGMP manufacturing facility;

•establish a commercialization infrastructure and scale up internal and external manufacturing and distribution capabilities to commercialize any product candidates for which we may obtain regulatory approval;

•adapt our regulatory compliance efforts to incorporate requirements applicable to marketed products;

•maintain, expand and protect our intellectual property portfolio;

•hire additional clinical, manufacturing quality control, regulatory, manufacturing and scientific and administrative personnel;

•add operational, financial and management information systems and personnel, including personnel to support our product development and planned future commercialization efforts; and

•incur additional legal, accounting and other expenses in operating as a public company.

To date, we have not generated any revenue from product sales. To become and remain profitable, we must succeed in developing and eventually commercializing product candidates that generate significant revenue. This will require us to be successful in a range of challenging activities, including completing preclinical testing and clinical trials of our product candidates, obtaining regulatory approval, and manufacturing, marketing and selling any product candidates for which we may obtain regulatory approval, as well as discovering and developing additional product candidates. We are only in the preliminary stages of most of these activities and all of our product

candidates are in clinical or preclinical development. We may never succeed in these activities and, even if we do, may never generate any revenue or revenue that is significant enough to achieve profitability.

Even if we 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 depress the value of our company and could impair our ability to raise capital, expand our business, maintain our development efforts, obtain product approvals, diversify our offerings or continue our operations. A decline in the value of our company could also cause you to lose all or part of your investment.

We have a limited operating history and no history of commercializing products, which may make it difficult for an investor to evaluate the success of our business to date and to assess our future viability.

We are a clinical-stage biopharmaceutical company with a limited operating history. We commenced operations in 2019, and our operations to date have been largely focused on organizing and staffing our company, business planning, raising capital, acquiring our technology and product candidates, acquiring our facilities in Tarzana, California, developing our manufacturing capabilities and developing our clinical and preclinical product candidates, including undertaking preclinical studies and conducting clinical trials. To date, we have not yet demonstrated our ability to successfully complete pivotal clinical trials, obtain regulatory approvals, manufacture a product on a commercial scale, 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 or a history of successfully developing and commercializing products.

We may encounter unforeseen expenses, difficulties, complications, delays and other known or unknown factors in achieving our business objectives. We will need to develop commercial capabilities, and we may not be successful in doing so.

We will need substantial additional funding to meet our financial obligations and to pursue our business objectives. If we are unable to raise capital when needed, we could be forced to curtail our planned operations and the pursuit of our growth strategy.

TIL US Equity

TIL · 10-K · period ended 2021-12-31

Item 1. Business.

Item 1A. Risk Factors.

TIL US Equity☆

TIL · 10-K · period ended 2021-12-31

Item 1. Business.

Item 1A. Risk Factors.

TIL US Equity