10-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2023

Commission File Number 001-39692

IN8BIO, INC.

(Exact name of Registrant as specified in its charter)

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (646) 600-6438

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, $0.0001 par value per share INAB The Nasdaq Stock Market LLC

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

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

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

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

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

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

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 13(a) of the Exchange Act. ☐

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

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the fi ling reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b) ☐

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

The aggregate market value of the voting and non-voting common equity held by non-affiliates of the Registrant, based on the closing price of $1.54 per share of the Registrant’s common stock as reported on the Nasdaq Stock Market LLC on June 30, 2023, the last business day of the Registrant’s most recently completed second quarter was $22.7 million. This calculation excludes shares of the registrant’s common stock held by current executive officers, directors and stockholders that the registrant has concluded are affiliates of the registrant. This determination of affiliate status is not a determination for other purposes.

The number of shares of Registrant’s Common Stock outstanding as of March 14, 2024 was 43,287,325.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the definitive proxy statement for the 2024 Annual Meeting of Stockholders of the Registrant, or the Proxy Statement, are incorporated by reference into Part III of this Annual Report on Form 10-K. The Proxy Statement will be filed with the Securities and Exchange Commission within 120 days of the Registrant’s fiscal year ended December 31, 2023.

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Table of Contents

Page

PART I

Item 1. Business 1

Item 1A. Risk Factors 46

Item 1B. Unresolved Staff Comments 91

Item 1C. Cybersecurity 91

Item 2. Properties 93

Item 3. Legal Proceedings 93

Item 4. Mine Safety Disclosures 93

PART II

Item 6. [Reserved] 94

Item 7A. Quantitative and Qualitative Disclosures About Market Risk 105

Item 8. Financial Statements and Supplementary Data 105

Item 9A. Controls and Procedures 127

Item 9B. Other Information 128

PART III

Item 10. Directors, Executive Officers and Corporate Governance 129

Item 11. Executive Compensation 129

Item 14. Principal Accountant Fees and Services 129

PART IV

Item 15. Exhibits and Financial Statement Schedules 130

Signatures

In this report, unless otherwise stated or the context otherwise indicates, the terms “IN8bio, Inc.,” “the company,” “we,” “us,” “our” and similar references refer to IN8bio, Inc. “IN8BIO,” “INEIGHTBIO,” “Cancer Zero,” the IN8BIO logo, DeltEx and other trademarks, trade names or service marks of IN8bio, Inc. appearing in this Annual Report are the property of IN8bio, Inc. All other trademarks, trade names and service marks appearing in this Annual Report are the property of their respective owners. Solely for convenience, the trademarks and trade names in this report may be referred to without the ® and TM symbols, but such references should not be construed as any indicator that their respective owners will not assert their rights thereto. The images found on pages 13, 17, 21 and 26 of this Annual Report were created with biorender.com and the image found on page 29 of this Annual Report was from BioPharma Dealmakers, March 2023.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K, or this Annual Report, contains statements that may constitute “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act, that involve substantial risks and uncertainties. All statements contained in this Annual Report on Form 10-K other than statements of historical fact, including statements regarding our future results of operations and financial position, our business strategy and plans, and our objectives for future operations, are forward-looking statements. The words “believes,” “expects,” “intends,” “estimates,” “projects,” “anticipates,” “will,” “plan,” “may,” “should,” or similar language are intended to identify forward-looking statements. These forward-looking statements include statements concerning the following:

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our ability to mitigate the substantial doubt to continue as a going concern;

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our estimates regarding expenses, future revenue, capital requirements and needs for additional financing;

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our plans to develop and commercialize our product candidates;

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the initiation, timing, progress and results of our current and future preclinical studies and clinical trials and our research and development programs;

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our ability to take advantage of abbreviated regulatory pathways for any of our product candidates;

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our ability to successfully acquire or in-license additional product candidates on reasonable terms;

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our ability to maintain and establish collaborations or obtain additional funding;

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our ability to obtain regulatory approval of our current and future product candidates, including our ability to file investigational new drug applications to commence additional clinical trials;

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our expectations regarding the potential market size and the rate and degree of market acceptance of such product candidates;

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our continued reliance on third parties to conduct clinical trials of our product candidates, and for the manufacture of our product candidates for preclinical studies and clinical trials;

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the implementation of our business model and strategic plans for our business and product candidates;

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our intellectual property position and the duration of our patent rights;

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developments or disputes concerning our intellectual property or other proprietary rights;

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our expectations regarding government and third-party payor coverage and reimbursement;

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our ability to compete in the markets we serve;

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the impact of government laws and regulations and liabilities thereunder;

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our need to hire additional personnel and our ability to attract and retain such personnel;

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developments relating to our competitors and our industry;

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our expectations regarding the impact of bank closures, public health crises and geopolitical tensions, such as the Russia-Ukraine and Israel-Hamas wars, on our business, our industry and the economy;

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our ability to contribute to eliminate cancer and achieve cancer-free status in any or all patients; and

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other factors that may impact our financial results.

You should not rely on forward-looking statements as predictions of future events. We have based the forward-looking statements contained in this Annual Report primarily on our current expectations and projections about future events and trends that we believe may affect our business, financial condition, and operating results. The outcome of the events described in these forward-looking statements is subject to risks, uncertainties and other factors described in the section titled “Risk Factors” and elsewhere in this Annual Report. A summary of selected risks associated with our business are set forth below. Moreover, we operate in a very competitive and rapidly changing environment. New risks and uncertainties emerge from time to time, and it is not possible for us to predict all risks and uncertainties that could have an impact on the forward-looking statements contained in this Annual Report. The results, events and circumstances reflected in the forward-looking statements may not be achieved or occur, and actual results, events or circumstances could differ materially from those described in the forward-looking statements.

In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based on information available to us as of the date of this Annual Report. And while we believe that information provides a reasonable basis for these statements, that information may be limited or incomplete. Our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all relevant information. These statements are inherently uncertain, and investors are cautioned not to unduly rely on these statements.

The forward-looking statements made in this Annual Report relate only to events as of the date on which the statements are made. We undertake no obligation to update any forward-looking statements made in this Annual Report to reflect events or circumstances after the date of this Annual Report or to reflect new information or the occurrence of unanticipated events, except as required by law. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures, or investments.

iii

PART I

Item 1. Business.

Overview

We are a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of gamma-delta T cell product candidates for solid and liquid tumors. Gamma-delta T cells are a specialized population of T cells that possess unique properties. They are naturally occurring immune cells that can intrinsically differentiate between healthy and diseased tissue. These cells serve as a functional bridge between innate and adaptive immunity to contribute to direct tumor killing, as well as immune cell recruitment and activation to drive deeper and more comprehensive immune responses. The pivotal role of gamma-delta T cells in immune function and activation against diseases such as cancer underscores their therapeutic potential across a wide range of solid and hematologic malignancies. We develop ex vivo-expanded and activated gamma-delta T cell candidates based upon our deep expertise in gamma-delta T cell biology, proprietary genetic engineering, and cell-type specific manufacturing capabilities, which we refer to collectively as our DeltEx platform. Our platform employs allogeneic, autologous, induced pluripotent stem cell, or iPSC, and genetically modified cell therapy approaches that are designed to effectively identify and eradicate tumor cells. We are the most clinically advanced gamma-delta T cell focused cellular therapy company and are utilizing our suite of DeltEx platform technologies as we aspire to eliminate cancer cells to achieve our mission of what we refer to as Cancer Zero ─ the safe elimination of all cancer cells in every patient battling the disease. We believe this lofty aspiration will one day be achievable and that it is our responsibility to directly contribute to related global health efforts by pursuing scientific research that will advance cancer treatment.

We recently initiated enrollment in our Phase 2 multi-center clinical trial of our lead product candidate, INB-400, for the treatment of newly diagnosed glioblastoma, or GBM. This trial will expand the assessment of autologous, genetically modified gamma-delta T cells in newly diagnosed GBM patients in specialized brain tumor centers across the United States. We anticipate that the Phase 2 trial will confirm the efficacy signal suggested by the investigator-initiated Phase 1 trial known as INB-200. We have completed enrollment of Cohort 3 for INB-200 and will provide clinical updates and long-term follow-up data at medical meetings throughout 2024. We presented an interim clinical update to INB-200 in an oral presentation at the American Society of Clinical Oncology, or ASCO, Annual Meeting 2023 and an update via poster at the Society of Neuro-Oncology or SNO Annual Meeting in 2023. In addition, with additional funding, we plan to submit an investigational new drug application, or IND, in 2025 for the Phase 1b/2 clinical trial of INB-400 in which allogeneic genetically modified gamma-delta T cells will be assessed in patients with recurrent and newly diagnosed GBM. Should a favorable safety profile be determined in the Phase 1b recurrent GBM portion of the study, we expect to initiate the Phase 2 expansion portion, whereby GBM patients with recurrent and newly diagnosed GBM would both be eligible to receive the allogeneic genetically modified gamma-delta T cell product. In April 2023, we received Orphan Drug Designation, or ODD, for the autologous and allogeneic INB-400 product from the FDA, covering a broad range of malignant glioma indications, including relapsed and newly diagnosed GBM.

In INB-100, the investigator-initiated Phase 1 trial for treatment of patients with high-risk leukemias undergoing hematopoietic stem cell transplantation, or HSCT, we determined a recommended Phase 2 dose, or RP2D. We have completed primary enrollment of the Phase 1 clinical trial and we presented a clinical update at the European Society for Blood and Marrow Transplantation, or EBMT Annual Meeting in April 2023 and at the American Society of Hematology, or ASH, Annual Meeting in December 2023. The complete remission or CR data to date, combined with INB-100’s benefit/risk profile are encouraging for the treatment of hematological malignancies and the trial is being expanded by 10 patients at Dose Level (DL) 2, the RP2D. Additional expansion patient enrollment is on-going and updated data is expected to be presented at medical meetings in 2024 with additional long-term follow-up results expected in 2025.

We also have a portfolio of preclinical programs in development, including INB-300, which focuses on addressing various solid and liquid tumors using a dedicated non-signaling gamma-delta T cell based chimeric antigen receptor T cell, or nsCAR, construct. We presented additional preclinical data demonstrating our proof-of-concept studies against the leukemia antigen targets CD19 and CD33, which demonstrated the ability of our nsCAR constructs to distinguish between tumor and healthy tissue at the American Association for Cancer Research, or AACR Annual Meeting in 2023 and at our Research and Development Day, or R&D Day, in October 2023. We expect to present an update at the 2024 AACR Annual Meeting in April.

In May 2022, we unveiled the expansion of our DeltEx platform capabilities to include induced pluripotent stem cell, or iPSC, derived gamma-delta T cells. iPSCs represent a significant step toward next generation approaches of cellular manufacturing for true allogeneic and potentially ‘off-the-shelf’ innate cell therapies. We provided updates in a presentation at the Society for Immunotherapy of Cancer, or SITC, Annual Meeting in November 2023 whereby to date, hundreds of millions of our iPSC derived iVdelta1+ or iVd1+ gamma-delta T cells have been produced from single iPSC clones at a low passage number. These cells demonstrate a profile associated with a reduced risk for cytokine release syndrome, or CRS and robust cytotoxic activity across a variety of solid and liquid cancers, including ovarian cancer, GBM, acute myeloid leukemia, or AML, and chronic myelogenous leukemia, or CML. Furthermore, cryopreservation did not impact the cells with the Vd1+ gamma-delta T cells showing comparable cytotoxicity to fresh cells, which allows them to be expanded and banked for potential on-demand

clinical use. These data highlight our ability to manufacture multiple gamma-delta T cell populations in a serum and feeder free process that can be scaled for GMP manufacturing and applied as a potentially ‘off-the-shelf’ platform for allogeneic cell therapy.

Chemotherapy, a mainstay of solid tumor treatment, can deplete and damage immune cells, limiting their ability to seek and kill tumors. Despite these limitations, chemotherapy continues to be used in standard-of-care regimens because of its ability to rapidly and directly kill tumors. Chemotherapy, however, can also result in residual tumor cells that are chemotherapy resistant and lead to disease recurrence. Recent studies show that the injury response to DNA damage from chemotherapy in tumor cells can promote anti-tumor immune activity and impact subsequent tumor rejection. These positive immune effects are obstructed by the lymphodepleting properties of chemotherapy, which can severely reduce the number of immune cells, such as gamma-delta T cells, that can seek out and kill the residual tumor cells. We have leveraged our proprietary genetic modifications of gamma-delta T cells to protect the cells from chemotherapy-induced damage, allowing for their concurrent delivery with chemotherapy. This could potentially enable our candidates to recognize and kill residual tumor cells, including chemotherapy-resistant cells and cancer stem-cells, by attacking at the time when the tumor is experiencing maximum chemotherapy-induced stress and vulnerability. We have termed this approach as our “DeltEx drug resistant immunotherapy,” or DeltEx DRI, and it is the basis for several of our programs. We were the first company to advance genetically modified gamma-delta T cells into the clinic and one of only two companies, to have produced gamma-delta T cells from iPSCs. In addition, we believe we are the only company to have demonstrated the ability to derive both Vd1+ and Vdelta2+, or Vd2+ gamma-delta T cells from iPSCs. In order to develop an off-the-shelf therapy, we are also testing the safety of a donor-derived, expanded, activated, non-genetically modified gamma-delta T cell therapeutic candidate, or DeltEx Allo, for the treatment of leukemia. We believe we are the first company to demonstrate the in vivo expansion and long-term persistence of allogeneic donor-derived gamma-delta T cells in the clinic.

Our DeltEx platform is designed to overcome many of the challenges associated with the expansion, genetic engineering, and scalable manufacturing of gamma-delta T cells. This approach allows us to expand the cells ex vivo to administer a potentially therapeutic dose to patients, harnessing the unique properties of gamma-delta T cells, including their ability to broadly recognize cellular stress signals on tumor cells. Our capabilities stem originally from the knowledge and experience now passed to our team by our scientific co-founder, Lawrence Lamb, PhD, who has been working with cellular therapies and specifically gamma-delta T cells since the early 1990s. Dr. Lamb published some of the earliest manufacturing methods for gamma-delta T cells and has extensive experience scaling and conducting GMP manufacturing. He was an inspector and auditor for the Foundation for the Accreditation of Cellular Therapy, or FACT, for over 20 years. We believe that our unique corporate insights into the advanced manufacturing and biology of gamma-delta T cells provide us with an innovative approach toward treating cancer that capitalizes on the particular properties of gamma-delta T cells. We have advanced three novel programs into the clinic that have the potential to demonstrate durable tumor responses. We have used the DeltEx platform to create our deep pipeline of innovative allogeneic, autologous, iPSC and/or genetically modified product candidates designed to effectively target and potentially eradicate disease and improve patient outcomes.

Going Concern

Our existing cash will only fund our operations into January 2025. We continue to deploy cash preservation measures to defer or reduce costs in the near term in order to preserve capital and increase financial flexibility. These cash preservation measures may impact our ability and the timing to execute our strategy, including our ability to achieve the anticipated milestones for our preclinical and clinical programs. To continue to fund our operations, management has developed plans, which primarily consist of raising additional capital through some combination of equity and/or debt offerings, including through our at-the-market offering, or ATM program, and identifying strategic collaborations, licensing or other arrangements to support development of our product candidates. In addition, pursuant to the December 2023 private placement, we may receive an additional $14.8 million in aggregate proceeds if the holders of our Series A ordinary warrants exercise their warrants pursuant to the mandatory exercise feature, which is triggered upon our public announcement of INB-100 data for the 10 currently enrolled patients, should they remain alive and evaluable, covering a period of at least 11 months of long-term follow-up for each patient, along with certain stock price and trading volume requirements. Further, if not otherwise redeemed by us, we may also receive aggregate proceeds of $17.7 million from the exercise of our outstanding Series B ordinary warrants issued in the December 2023 private placement. There is no assurance, however, that we will receive any additional proceeds from the December 2023 private placement or that any additional financing or any revenue-generating collaboration will be available when needed, that management will be able to obtain financing or enter into a collaboration on terms acceptable to us, or that any additional financing or revenue generated through third-party collaborations will be sufficient to fund our operations. Accordingly, the report from our independent registered public accounting firm for the year ended December 31, 2023, includes an explanatory paragraph stating that our recurring losses since inception raises substantial doubt about our ability to continue as a going concern.

If additional capital is not available to us on a timely basis, or at all, we will be required to take additional actions beyond the cost preservation measures initiated to address our liquidity needs, including to explore other strategic options, continue to further reduce operating expense or to delay, reduce the scope of, discontinue or alter our research and development activities. If we do not obtain additional financing and are required to terminate our operations, our stockholders will lose their investments.

Our Pipeline

The following chart shows the developmental status and the next anticipated milestones of our clinical and preclinical product candidates, all of which are wholly owned. The timing of the next anticipated milestones below and the related discussion throughout this Business section are estimates based upon the receipt of additional capital to fund our programs. See “—Going Concern” for additional information:

Figure 1. Pipeline Chart

INB-200 is a genetically modified autologous gamma-delta T cell product currently in a Phase 1 clinical trial. In preclinical studies, our DeltEx DRI technology has been shown to allow gamma-delta T cells to survive and remain functional at therapeutic and supratherapeutic concentrations of chemotherapy. Such levels, which would normally be toxic to immune cells, demonstrate the ability of our DeltEx DRI gamma-delta T cells to be used concomitantly with chemotherapy for the treatment of multiple solid tumor cancers. We engineered INB-200 to be resistant to alkylating agents such as temozolomide, or TMZ, and the nitrosources as a class of chemotherapeutic drugs designed to be used in the treatment of GBM and other cancers. This could allow INB-200 to be administered in combination with the current standard-of-care in the newly diagnosed treatment setting where median overall survival has remained at 14 to 16 months since 2005. In preclinical studies, we demonstrated that such concomitant combinations resulted in durable improvements in long-term overall survival and complete eradication of tumor in 80% of animals. The current INB-200 Phase 1 clinical trial is a dose escalation protocol for newly diagnosed GBM patients at the Heersink School of Medicine and O’Neal Comprehensive Cancer Center at the University of Alabama at Birmingham, or UAB. The protocol is designed to evaluate single and multi-dose schedules of a fixed concentration of DeltEx DRI gamma-delta T cells. We have completed enrollment of Cohort 3 and expect to provide clinical updates throughout 2024 and long-term follow-up in 2025.

INB-100, our first allogeneic DeltEx product candidate, was developed to demonstrate the safety of donor-derived expanded and activated gamma-delta T cells that do not undergo additional genetic modification. This product candidate is being administered in a dose-escalation Phase 1 clinical trial for the treatment of patients with high-risk hematologic malignancies that are undergoing allogenic HSCT. Acute myeloid leukemia, or AML, and acute lymphoblastic leukemia, or ALL, represent two of the three most common allogeneic HSCT-treated cancers, accounting for approximately 50% of all allogeneic HSCTs. We have developed scalable methods to expand and activate gamma-delta T cells from peripheral blood in an automated manufacturing device. Prior clinical observations have shown that high numbers of circulating gamma-delta T cells have been correlated with improved survival outcomes in HSCT patients. This Phase 1 dose-escalation clinical trial of INB-100 in allogeneic HSCT patients is being conducted at the University of Kansas Cancer Center. We currently expect to complete enrollment of the expansion cohort of this Phase 1 clinical trial in 2024, with updated results throughout 2024. Topline results of the expansion cohort currently being enrolled are expected in 2025.

INB-400 is in Arm A of the Phase 2 clinical trial using our autologous DeltEx DRI product candidate to treat newly diagnosed GBM. The INB-400 clinical trial will further confirm the clinical efficacy of DeltEx DRI therapy in a large national multicenter trial. Patient enrollment in the autologous Arm A was initiated and we currently expect to report initial data from the Phase 2 clinical trial in 2025. Per FDA Guidance for Industry finalized on November 4, 2022, allogeneic product candidates constitute a separate drug product and require a separate IND. Arms B and C of the INB-400 trial will evaluate the safety of genetically modified, allogeneic DeltEx DRI gamma-delta T cells in both the relapsed and newly diagnosed GBM patient populations. Clinical data and experience from the Phase 1 clinical trials of INB-200 and INB-100 will be utilized to support submission of an IND for the allogeneic arms of INB-400 expected in 2025. We believe this is the first time a similar gene-edited construct has been tested in both the autologous and allogeneic settings.

We are also developing a broad portfolio of preclinical programs utilizing the unique biology of gamma-delta T cells in our efforts to achieve our mission of Cancer Zero. INB-300 is a preclinical program focused on developing unique nsCAR-enabled DeltEx product candidates with which we expect to target difficult liquid tumors and extracranial solid tumors. The current generation of CAR-T products on the market and in development seek to destroy specific antigen targets such as CD19, CD20, BCMA, CD33, and CD123 among others. These CAR-Ts eliminate tissues expressing the target irrespective of whether they are tumor or healthy tissues. Early data from the CD19 CAR-Ts demonstrate that they drive aplasia of the normal and malignant B-cell compartment. This becomes problematic as many selected antigen targets are also expressed on healthy tissues that are crucial for the continuation of life, especially in solid tumor cancers. Our gamma-delta based nsCAR technology is focused on addressing this challenge in various solid and liquid tumors. Our nsCAR platform uses the innate immune recognition of gamma-delta T cells to distinguish between tumor and healthy tissue, offering a targeted but potentially less toxic approach. These constructs lack a CD3z signaling domain that would typically force T cell activation through the CAR and antigen binding domain. Instead, this T cell utilizes the CAR to localize to the target tumor cells and T cell activation is triggered by the endogenous receptors of the gamma-delta T cell including NKG2D, CD16, toll-like receptors, and gamma-delta TCR among others to actually induce killing of the target tumor cells. The nsCAR platform has demonstrated a greater than 15x difference in killing between leukemic cells and healthy B cells (effector to target, or E:T, ratio=2:1, 79.7% versus 5.2%) when both express the CD19 target antigen. The nsCAR platform can also be engineered to express the cytokine interleukin-15 (IL-15) to enhance cellular persistence and the ability to target and kill tumor cells over time. At our R&D Day in October 2023, we presented the initial data of an nsCAR targeting CD33 and co-expressing IL-15 for AML. Initial cytotoxicity data demonstrated ns33CAR+IL-15 killing of approximately 3% against CD34+ hematopoietic progenitor cells, or HPCs versus an average of approximately 65% killing against three separate AML cell lines at an E:T ratio of 8:1. We expect to provide additional preclinical updates on this program at the 2024 AACR conference in April 2024. We believe that the platform has the potential to broaden the utilization of CAR technology for previously “undruggable” solid and liquid tumor targets. Additional internal programs are focused on advanced manufacturing methodologies such as iPSCs and on logical combinations with other therapies approved by the FDA.

As of December 31, 2023, our intellectual property portfolio consists of 10 patent families that broadly protect our DeltEx platform and our product candidates, both through composition of matter and method of use. Our patents broadly cover genetic modification to gamma-delta T cells that confers chemotherapy resistance. Our future product candidates could incorporate additional proprietary genetic alterations designed to make them resistant to other chemotherapies utilized to treat multiple types of solid tumor cancers. Our patents also cover the method of generating these genetically engineered cells from patients or donors and their use in multiple solid and liquid tumors. Our portfolio broadly covers the use of allogeneic gamma-delta T cells in HSCT. Finally, we have patent families that cover the composition of our CAR constructs in gamma-delta T cells, specifically in our DeltEx DRI cells, and their use in multiple solid and liquid tumors.

Our Strategy

We are dedicated to leveraging our DeltEx platform to develop next generation cell therapies that we believe can dramatically improve outcomes for cancer patients in our efforts to achieve our mission of Cancer Zero. To achieve this goal, our strategy is as follows, which is dependent on our ability to raise additional capital or successfully deploy other strategic options:

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Continue advancing our lead clinical product candidates, INB-400, INB-200 and INB-100. INB-200 is our autologous DeltEx DRI program that we are initially developing for the treatment of newly diagnosed GBM. We are conducting a Phase 1 dose-escalation clinical trial assessing single and multiple dosing schemas at UAB. We expect to complete enrollment of Cohort 3 with clinical updates expected throughout 2024 and long-term follow-up in 2025. We are conducting a Phase 2 multi-center clinical trial of INB-400, our company-sponsored clinical program using our autologous DeltEx DRI product candidate to treat newly diagnosed GBM. We have initiated patient enrollment and expect to report initial data from the Phase 2 clinical trial in 2025. We are also conducting a Phase 1 dose escalation clinical trial of INB-100, our allogeneic DeltEx product candidate in patients with hematologic malignancies undergoing allogeneic HSCT, from which we currently expect to complete enrollment of the expansion cohort of the Phase 1 clinical trial in 2024, with updated results throughout 2024 and topline results in 2025.

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Advance INB-500 and INB-300 into clinical development, subject to receiving authorization from FDA pursuant to company-sponsored INDs. INB-300 is a DeltEx nsCAR construct, for which we are testing various antigen recognition domains in our efforts to advance a program to IND enabling studies. We expect to present additional data demonstrating our progress and proof-of-concept for this program at the 2024 AACR Annual Meeting. INB-500 is the expansion of our DeltEx platform capabilities to include iPSC derived gamma-delta T cells. Our feeder cell and serum free expansion and differentiation protocols have demonstrated an ability to generate both Vd1+ and Vd2+ gamma-delta T cell subclones. These cells have high-cytotoxicity, and we are exploring avenues for advancement and potential partnering.

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Leverage our DeltEx platform for additional indications and product candidates. We will continue to advance internal research including the application of our proprietary DeltEx DRI approach into additional liquid and solid tumor indications. We are also developing additional discovery programs that could incorporate additional proprietary genetic modifications in our DeltEx platform designed to address both solid and liquid tumors. We expect to submit several INDs using technology assessed in INB-100, INB-200 and INB-400, including in combination with other therapeutics and in other solid tumors outside of GBM over the next several years.

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Advance and continue to scale our manufacturing. We have established an automated, closed-system, reproducible, scalable manufacturing platform. We will continue to focus on expanding manufacturing capacity and capabilities along with advanced manufacturing methods to support our ongoing and anticipated clinical development. In addition to using collaborators such as the Dunbar CAR-T Cell Program at the University of Louisville and contract manufacturers, we plan to build internal manufacturing capabilities as we demonstrate clinical proof-of-concept, leveraging our company know-how and collaborators for product delivery, logistics and capacity expansion across our parallel processes.

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Independently develop and commercialize our product candidates where we believe we can maximize their value and benefit to patients. Given the broad applicability of our DeltEx technology pipeline across multiple solid and liquid tumor indications, we plan to maximize its value by retaining development and commercialization rights to the product candidates, indications, and geographies that we believe we can commercialize successfully on our own, pending regulatory approval. We plan to collaborate on candidates that show promising utility in disease indications, patient populations or geographies that we believe would be better served by the resources, specific expertise or commercial abilities of other biopharmaceutical companies or partners.

Gamma-Delta T Cells: Leveraging the Nexus of the Immune System

The Rise of Cell Therapy

There has been significant recent innovation in the treatment of cancer, including novel biological and cell therapies. Immuno-oncology utilizes the immune system to identify and kill cancer cells. Such therapies can either prevent the tumor’s ability to suppress immune attack or to directly utilize immune cells to target and kill cancer cells. The immune system consists of complex and highly evolved groups of cells that have the ability to target dangerous pathogens and damaged or sick tissue to keep the body safe. The system is generally comprised of two functional branches, the innate and the adaptive. Gamma-delta T cells are endowed with at least two independent recognition systems to sense tumor cells and to initiate anticancer killing by recruiting and activating multiple immune cell types.

The innate and adaptive immune responses both play critical roles in the fight against cancer. While both systems possess critical functions, the most effective tumor killing occurs when they work in concert. As shown in Figure 2 below, gamma-delta T cells sit at the nexus of the two systems and possess a powerful combination of both innate and adaptive cell properties. They can directly kill without prior antigen priming, similar to certain innate cells, such as NK cells, but can also function to present antigen directly to drive cytokine release and to target neoantigens through antigen mediated cell killing.

Figure 2. Gamma-Delta T Cells: Innate and Adaptive Immune System Characteristics

Most cell therapy approaches utilize either the adaptive immune system, such as alpha-beta T cells, or the innate immune system, such as NK cells. These approaches have certain inherent limitations, particularly against solid tumors. Taken together, the unique properties of gamma-delta T cells indicate that their therapeutic application can overcome many of these challenges. Simplistically, gamma-delta T cells are a combination of both worlds, with the memory and persistence features of the adaptive immune cells along with the recognition, killing and safety features of the innate immune cells.

Inherent Limitations of Current Cell Therapy Approaches

A common approach in cell therapy involves the use of genetically engineered CARs on a T or NK cell that enable it to recognize a specific protein or antigen that may be present on the surface of tumor cells. The CAR bypasses the normal biology of T and NK cells, by driving their activation through the binding of the CAR-directed antigen. While effective for direct antigen recognition, the inherent heterogeneity of solid tumors means that it is unlikely that any single antigen will be expressed by all tumor cells.

Since 2017, the FDA has approved multiple autologous CAR-T cell therapies, KYMRIAH®, Yescarta®, Breyanzi®, Abecma® TECARTUS®, and CARVYKTI®, which have been transformative in the treatment of certain hematological cancers, but CAR-Ts have had extremely limited efficacy in solid tumors to date. This lack of efficacy in solid tumors underscores the inherent challenges of CAR-T approaches. Many of the limitations of CAR-T cell therapies are related to the fundamental dynamics of solid tumors and T cell biology. This includes (i) the potential inability to effectively target the entire tumor using a single antigen CAR due to tumor heterogeneity, (ii) the potential inability to effectively penetrate the tumor microenvironment, or TME, due to physical barriers such as tumor bulk, (iii) the lack of tumor antigens, which are ubiquitously and uniquely expressed on tumor cells, (iv) potential limited T cell function due to the immunosuppressive TME, including regulatory T cells, or Tregs, and other immune-suppressive cells, (v) limited ability to efficiently deliver cells directly to the tumor site to generate a high effector to target, or E:T ratio, and (vi) the inability to combine with effective chemotherapeutic regimens due to the chemosensitivity of immune cells. Additional challenges that have potentially hampered widespread adoption of existing CAR-T technologies include scalability, safety and cost.

In recent years, there has been increasing focus on CAR-NK cell therapies, with multiple programs currently in development. NK cells are innate immune cells that possess the ability to detect and kill cancer cells by recognizing common

antigens without highly selective adapted receptors towards specific antigens. Their cytotoxicity is mainly dependent on the balance between activating and inhibitory signals, such as killer cell immunoglobulin-like receptors, or KIRs, which can be overcome with the addition of CARs to allow for their use in cell therapy. CAR-NKs are attractive over alpha-beta CARs for two primary reasons: (i) CAR-NKs do not express the cytokine IL-6, one of the major drivers of cytokine release syndrome, or CRS, which can lead to substantial morbidity and mortality with immune CAR-T therapies; and (ii) CAR-NKs are not major histocompatibility complex, or MHC, restricted and can be infused from a donor to a patient without complex and expensive genetic engineering to prevent graft versus host disease, or GvHD.

Despite these advantages, the development of CAR-NKs has faced several key challenges — in particular, manufacturing difficulties and limited scalability, their sensitivity to cryopreservation leading to a loss of viability and cytotoxicity, a limited ability to efficiently introduce genetic modifications, and lower cell persistence. Importantly, against solid tumors, the addition of a CAR to overcome KIR inhibition in an NK cell overrides their endogenous ability to target multiple receptors and results in a single antigen targeting CAR with the same limitation towards relapse due to tumor heterogeneity and ultimately antigen escape as a traditional CAR-T. In 2023, early CAR-NK cell clinical data provided to be disappointing due to the lack of persistence of NK cell based cellular therapies and their durability of response. Data published in a major journal in early 2024 demonstrated that NK cells that enter the solid tumor microenvironment can be rapidly reprogramed into dysfunctional tissue resident cells that lack effector function and anti-tumor activity. These observations have resulted in significant pipeline changes and the termination of multiple programs by major biotechnology and pharmaceutical companies developing NK or iNK cell therapies in 2023.

The inherent and engineered limitations of these therapies, particularly in the solid tumor setting, creates substantial opportunity for improved and differentiated cell therapies for cancer.

Why Gamma-Delta T Cells?

Gamma-delta T cells are a unique subset of immune cells that sit at the nexus of the innate and adaptive immune systems and possess properties of both, performing diverse immune functions including protection against tumors. This combination of features conveys functional abilities that make them ideally suited for use in cell therapy against cancer. They typically account for up to 10% of T cells but can undergo rapid activation and expansion in response to diseased or damaged tissue. As gamma-delta T cells bridge between the innate and adaptive immune response, they are thought to have greater persistence than NK cells. Our own histopathological data from the INB-200 clinical trial has demonstrated both an increase in the number gamma-delta T cells and their continued presence in the tumor microenvironment, or TME, approximately 150 days following infusion of our DeltEx DRI modified gamma-delta T cells. The University of Pennsylvania published data in the journal Nature in February 2022 that demonstrated decade-long leukemia remissions in two patients with chronic lymphocytic leukemia. The data showed persistence of highly activated CD4+ CAR-T cells including a large population of gamma-delta CAR-T cells that prominently expanded in one patient along with CD8+ CAR T cells. More recently, surprising data from our own INB-100 program in leukemia patients undergoing HSCT has demonstrated the in vivo expansion and long-term persistence of allogeneic gamma-delta T cells now for as long as 365 days.

Gamma-delta T cells are multifunctional with a complex receptor repertoire including the semi-invariant T cell receptor, or TCR, which allows them to distinguish between healthy and diseased or stressed tissue. This distinct mode of antigen recognition is a critical feature that distinguishes them from not only alpha-beta T cells but also B cells and NK cells. Gamma-delta T cells can kill effectively, both by direct cellular killing as well as the recruitment of additional immune cell types to induce killing. Importantly, gamma-delta T cells can kill in situations where other immune cells cannot, such as alpha-beta T cells through the downregulation of MHC expression NK cells through inhibition by matched KIR.

Figure 3. “Nature’s CAR-T Cell”

Gamma-delta T cells have been referred to as “nature’s CAR-T cells” because their complex antigen recognition allows them to naturally and effectively target and eliminate diseased tissues, such as tumor tissue. As shown in Figure 3, their diverse receptor repertoire may enable them to recognize and target the array of heterogeneous antigens expressed by solid tumors, which has been a significant challenge to existing single-antigen targeting CAR technologies using NK and alpha-beta T cells.

Gamma-delta T cells also have the inherent ability to recognize a broad array of cellular stress signals, leading to both direct tumor cell killing as well as activation of a multifaceted immune response. Gamma-delta T cells have been observed to directly recognize and respond to a variety of MHC-like stress-induced self-antigens expressed by malignant cells without previously having the antigen presented, similar to NK cells. This recognition of stress antigens is achieved through a combination of gamma-delta TCRs, natural killer receptors, or NKRs, such as NKG2D, DNAM-1, and toll-like receptors, or TLRs. This diversity of receptors is central to gamma-delta T cells’ ability to identify healthy versus diseased tissue and may also contribute to their ability to effectively target cells, such as tumor cells with high variability and/or heterogeneity, thereby reducing antigen escape as shown in Figure 4.

Figure 4. Innate Immune Cell Receptors of Gamma-Delta T Cells

The following highlights key potential advantages of gamma-delta T cells in comparison to other cell therapies for cancer:

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Differentiate between healthy and cancer cells. By using a combination of signaling receptors, including gamma-delta TCR, NKG2D, DNAM-1, and TLR, among others, gamma-delta T cells can safely distinguish between safe and dangerous tissues, such as cancerous tissues, within the body.

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Broad tumor recognition overcomes surface antigen heterogeneity. The tumor contains cells that express a variety of antigen targets at different levels of expression. The complex and polyclonal binding abilities of gamma-delta TCR and NKG2D receptor allow them to broadly target diseased tissue and cover the heterogeneity of the tumor.

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Recruit and activate additional immune effector cells. Gamma-delta T cells broaden the immune response both through secretion of effector cytokines and chemokines that recruit and stimulate immune cells at the tumor. Gamma-delta T cells can elicit dendritic cell, or DC maturation by conveying danger associated molecular patterns, or DAMPs, and pathogen associated molecular patterns, or PAMPs to such cells. Certain subtypes of gamma-delta T cells also function directly as professional antigen presenting cells, or APCs, that activate and instruct alpha-beta T cells, similar to other innate immune cells like DCs, in order to elicit a potent and selective adaptive immune response.

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Safety advantages over other cell therapies. Gamma-delta T cells do not recognize allogeneic MHC restricted antigens and thereby can be obtained from a partially matched or even unmatched donor, which may eventually allow these cells to be used ‘off-the-shelf’. Gamma-delta T cells also do not secrete IL-6, a significant driver of CRS, which has been a fatal complication in CAR-T in acute leukemias.

How Gamma-Delta T Cells Kill

The biology of gamma-delta T cells is complex, with multiple mechanistic approaches to effectively recognize, target and directly kill tumor cells, as shown in Figure 5 below. This allows them to drive towards deeper immune responses through immune cell recruitment and activation, cytokine release and antigen presentation:

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Induction of cellular apoptosis. Fas ligand, or CD95L, and tumor necrosis factor-related apoptosis-inducing ligand, or TRAIL, are both well-known triggers of cell death. These proteins are expressed on gamma-delta T cells, which allows them to engage the death receptors on target cells, leading to the direct destruction of cancer cells.

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Secretion of cell-killing enzymes and proteins. Gamma-delta T cells secrete granzymes, cell killing enzymes, that are typical of killer cells and cytotoxic T cells, and perforin, a protein that opens a hole in the target cell, allowing for the entry of granzymes. This can lead to apoptosis, or programmed cell death, in the same manner as NK cells.

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Antibody-dependent cellular cytotoxicity. Antibody-dependent cellular cytotoxicity, or ADCC, is cell-mediated cell killing, an efficient killing mechanism employed by the immune system. ADCC is triggered by the recognition of tumor-targeting antibodies through the CD16 expressed on gamma-delta T cells, similar to NK cells. This mechanism could allow the combination of gamma-delta T cell therapy with FDA-approved monoclonal antibody therapeutics, such as Rituxan, designed to enhance the effect of the antibody.

Figure 5. Multiple Cell-Killing Mechanisms of Activated Gamma-Delta T Cells

Opportunities for Gamma-Delta T Cells in Cancer

The therapeutic potential of gamma-delta T cells is supported by observations over 30 years demonstrating a significant clinical correlation between naturally occurring high levels of gamma-delta T cells and better survival outcomes in both hematologic and solid tumor cancers. Our scientific founder and Chief Scientific Officer, Dr. Lamb, was the first person to report an association between levels of gamma-delta T cells and improved survival in leukemia patients undergoing allogeneic HSCT. His work, published in J. Hematotherapy in 1996, and expanded on in a publication in Cytotherapy in 1999, found that the disease-free survival rate of HSCT patients who received T cell depleted, or TCD, grafts from a partially matched donor increased in those with high levels of gamma-delta T cells. These findings have been supported by reported studies from other scientists. In 2007, Dr. Lamb and his collaborators found that the association between post-transplant gamma-delta T cells and survival as depicted in Figure 6 below, extended to at least seven years, and that 71% of patients with high levels of gamma-delta T cells survived up to seven years compared to 20% of patients with low levels of gamma-delta T cells.

Figure 6. Correlation of Naturally Occurring Gamma‐Delta T cells and Long‐Term Survival in Leukemia

A Stanford University analysis of tumor-infiltrating immune cells in approximately 18,000 human tumor samples found that among all the subtypes of immune cells analyzed, the presence of gamma-delta T cells as tumor infiltrating lymphocytes, or TILs, was the most highly correlated with overall survival, as shown in Figure 7 below. Patients with solid tumors containing gamma-delta T cells were significantly more likely to improve and potentially survive than those without gamma-delta T cells present.

Figure 7. Prognostic Association of Tumor Infiltrating Lymphocytes and Survival Outcomes

While gamma-delta T cells have demonstrated clinical association with specific tumor responses, there have been significant hurdles to developing them as cell therapies, particularly for solid tumors. Gamma-delta T cells comprise less than 10% of all lymphocytes found in the body, and as such have been challenging to manufacture in quantities sufficient to meet the significant

doses generally required for efficacious cellular therapies. In addition, as cancer progresses, the levels of gamma-delta T cells are further reduced, making it challenging to engage them in vivo. Finally, gamma-delta T cells are critical in identifying stress antigens on diseased tissue, such as tumor cells. These signals can be dramatically upregulated by chemotherapy, which stresses both the chemotherapy-sensitive and chemotherapy-resistant tumor cells, making them readily identifiable by gamma-delta T cells. Chemotherapy can both kill the immuno-suppressive cells and induce tumor cell death to “de-bulk” the tumor. This opens the TME to effector cells, such as gamma-delta T cells. However, chemotherapy also depletes and damages immune cells, including gamma-delta T cells, limiting their ability to seek and kill tumor cells.

Preclinical Studies Have Demonstrated a Role for Gamma-Delta T Cells in Cancer

The clinical observations described above are supported by a broad base of preclinical research. Gamma-delta T cells have been shown to play a significant role in tumor immunosurveillance. Preclinical studies have demonstrated that genetically engineered mice deficient in gamma-delta T cells were highly susceptible to carcinogen-induced skin cancers. Similarly, prostate cancer growth was accelerated in mice deficient for gamma-delta T cells compared to fully immunocompetent mice. Gamma-delta T cells have been detected in a variety of human tumor types, including GBM, neuroblastoma and lung cancer, demonstrating that gamma-delta T cells infiltrated such solid tumors and thus may have an important correlation with anti-cancer activity. Prior data, including our own unpublished studies, have indicated that levels of gamma-delta T cells were diminished as cancer progresses and were depleted in end-stage disease.

Our Approach

We develop ex vivo-expanded activated gamma-delta T cells based upon our deep expertise in gamma-delta T cell biology, proprietary genetic engineering, and cell-type specific manufacturing capabilities, which we refer to collectively as our DeltEx platform. Our platform is designed to overcome many of the challenges associated with expansion, genetic engineering, and scalable manufacturing of gamma-delta T cells. This allows us to expand the cells ex vivo to administer a potentially therapeutic dose to patients, harnessing the unique properties of gamma-delta T cells, including their ability to broadly recognize cellular stress signals on tumor cells. DeltEx has enabled our deep pipeline of innovative allogeneic, autologous, iPSC and/or genetically modified product candidates designed to effectively target and potentially eradicate disease and improve patient outcomes. Key elements of our platform include:

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Expertise in ex vivo-expanded activated gamma-delta T cells. Gamma-delta T cells, while critical to immune function and disease response, account for only a small percentage of our immune cells. Our approach leverages our scientific expertise in gamma-delta T cell biology, encompassing the work of our scientific founder Dr. Lamb, to perform precise cell-type specific ex vivo expansion. This enables us to take peripheral blood from the patient and selectively expand the low numbers of gamma-delta T cells to generate a sufficient dose for treatment of solid tumors. Our expertise allows us to expand the desired subtypes of the gamma-delta T cell population, perform specific genetic modifications, and complete a quality review of these cells before returning precisely controlled doses to patients. This precision, control and quality provides significant advantages over in vivo expansion, which may not be cell-type specific, and we believe it uniquely enables us to potentially develop a therapeutic candidate at scale.

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Intelligent gamma-delta T cell genetic engineering. We have developed proprietary methods of engineering gamma-delta T cells that are designed to take advantage of their inherent biology. Our engineering is designed to increase their ability to survive chemotherapy or to identify cancer cells while maintaining their natural ability to broadly recognize, engage and kill these cells while preserving healthy tissue. This enables the cells to be delivered concurrently with chemotherapies that activate the DNA damage response, or DDR, pathway to generate an immune signal that should be expressed on all cells throughout the tumor and recognized by gamma-delta T cells. This intelligent engineering is broadly applicable across multiple solid tumor indications. Our approaches have overcome the historical problems in genetically modifying gamma-delta T cells, and we were the first company to advance a Phase 1 clinical trial using genetically modified gamma-delta T cells.

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Next-generation gamma-delta T cell manufacturing. We have devoted significant time and resources to process development and manufacturing to improve the quality and reproducibility of our processes. Through our intellectual property and scientific know-how, we have designed and implemented a manufacturing process, including proprietary programs, which is designed to be reliable and scalable. We have automated our manufacturing processes, which are currently operating at clinical scale, in a system designed to minimize touchpoints and potential contamination and increase throughput. Our cell-type specific manufacturing platform is designed to support rapid development of our DeltEx product candidates through clinical trials and the regulatory approval process. We are using an automated, fully enclosed system for cell manufacturing, as shown in Figure 8 below, that is designed to be applicable across our current product candidates. Our manufacturing allows us to scale, while maintaining quality controls, which would be challenging with a manual lab-scale process. We have optimized transduction and cell expansion in a process we

believe can be rapidly scaled for commercial supply in a controlled environment at a reasonable cost, if any of our product candidates are successfully developed and approved. We have also demonstrated successful cryopreservation and delivery of our thawed product candidates to patients in our clinical trials, while maintaining cell viability and functionality.

Figure 8. Reproducible & Scalable Manufacturing Process

Scientific Basis for Vd2+ Versus Vd1+ Gamma-Delta T Cells as Therapy for Solid Tumors

There are several diverse subsets of gamma-delta T cells. The most predominant circulating subsets are the Vdelta2 positive, and the Vdelta1 positive. These cell types have specific features that impact their therapeutic potential across different indications. Vd2+ cells comprise approximately 2 to 10% of the circulating cell population. The Vd1+ cells are a minor (<2%) circulating subset, but abundant in specific tissues, such as the intestines and the skin. While both subsets express NKG2D receptors that recognize stress ligands, only the Vd2+ subset can function as a professional APC, which can process and present antigens, recruit and activate additional immune cell types, a function that has not been documented for the Vd1+ T cell compartment and may make the Vg9Vd2 subset more attractive for use in solid tumor cancers. While there may be a potential utility for the Vd1+ subset for some cancers, we are currently focused on developing therapeutic candidates using Vd2+ cells, which we believe may have certain advantages over the Vd1+ subset in certain indications. While Vd1+ cells have previously shown greater persistence in the autologous setting, this increased persistence in the allogeneic setting (other than allogeneic HSCT) may be irrelevant as host immune system recovery could result in their rejection by host NK cells which recover following lymphodepletion within approximately 15 to 30 days. Additionally, Th1 effector Vd1+ cells can be reprogrammed to a tumor promoting Th17, or IL-17 secreting, subtype after entering the microenvironment of certain tumors. While current ex vivo expansion methods for Vd1+ cells have not resulted in pro-tumorigenic Th17-type responses to date, the potential for reprogramming of therapeutic Vd1+ cells within the TME remains a possibility. In contrast, Vd2+ cells are not known to produce Th17 or pro-tumoral subtypes.

We are a gamma-delta T cell company and are agnostic to Vd2+ versus Vd1+ subtypes. We believe each has a role and indications in which they may make sense based on the tumor biology and desired cellular mechanism of action. Our CSO, Dr. Lamb was in fact the first to publish a protocol for the expansion and manufacturing of Vd1+ gamma-delta T cells in 2001. We are currently advancing programs utilizing both Vd2+ and Vd1+ cells, using our cell-type specific expansion protocols. We have developed our DeltEx platform to enable us to expand, activate and genetically modify gamma-delta T cells at scale, producing cells which are viable, functional and can be cryopreserved while maintaining their cytotoxicity.

Our Product Candidates

INB-200 for the Treatment of Solid Tumors

INB-200 is our novel genetically modified autologous DeltEx product candidate that we are developing for the treatment of solid tumors. We engineered INB-200 to be used as an adjunct to the current standard-of-care treatment by engineering it to be resistant to certain types of alkylating chemotherapies. Alkylating chemotherapies function by creating DNA damage and strand breaks that lead to cell suicide or apoptosis. The protein O-6-Methylguanine-DNA Methyltransferase, or MGMT, is a primary DNA repair protein capable of repairing damage to DNA caused by certain chemotherapies that prevents cell death. Through the

introduction of a gene encoding MGMT into gamma-delta T cells, these genetically modified DeltEx DRI cells are designed to survive concurrent dosing with chemotherapy and remain functional. In preclinical studies in patient-derived xenografts, published in the Nature portfolio journal Scientific Reports in October 2021, INB-200 demonstrated antitumor activity, including long-term survival and eradication of the tumor as evidenced by histopathology. We are initially developing INB-200 to treat newly diagnosed patients with GBM during the maintenance phase following resection and initial radiation and chemotherapy. We are conducting an investigator-initiated Phase 1 clinical trial assessing multi-dose schedules in patients with newly diagnosed GBM, which was initiated by L. Burt Nabors, M.D. at UAB. We completed enrollment of Cohort 3 in 2023, with clinical updates expected throughout 2024 and long-term follow-up in 2025.

GBM Overview

GBM is a particularly aggressive form of brain cancer, in which tumor cells invade the surrounding neural tissue, rendering a cure with surgical resection and chemotherapy unlikely. The incidence of GBM in the United States is estimated to be approximately three in 100,000 individuals, with almost 14,500 new cases having been estimated in 2023 by the National Brain Tumor Society. Surgical resection followed by radiation and TMZ has been the current standard-of-care since 2005, but it is only able to control tumor growth in approximately 30% of patients. Based on current standard-of-care, tumor recurrence typically occurs within one year after initial diagnosis and treatment. A third-party trial published in 2017 indicated that older newly diagnosed GBM patients with unmethylated MGMT treated with radiation therapy and TMZ had median progression free survival of only 4.8 months (95% CI (4.3-5.6)) while median overall survival for GBM patients remains about 16 months irrespective of tumor methylation status. Ultimately, virtually all patients will relapse, creating a significant unmet medical need with a potential global market opportunity greater than $4 billion.

Our Solution — INB-200 and INB-400 for the Treatment of Newly Diagnosed GBM

We engineered INB-200 using a lentiviral vector to introduce the gene for MGMT, which is the primary protein capable of repairing DNA damage caused by alkylating chemotherapeutic drugs, such as TMZ. Tumor cells that over-express MGMT are resistant to TMZ and the current standard-of-care in GBM. By introducing MGMT into our DeltEx gamma-delta T cells, these genetically modified cells are designed to avoid TMZ-induced cell death. There is also considerable preclinical support for the use of gamma-delta T cells for the treatment of GBM.

There is a significant unmet need as most patients with GBM die within 15 to 16 months of diagnosis and the five-year survival rate is approximately 5%. Over 80% of treated GBM patients recur within 2cm of the original resection site, suggesting that recurrence is not due to metastases, but due to local microscopic residual tumor cells that were not surgically resectable and that may be resistant to radiotherapy and chemotherapy. We believe that to have a clinically meaningful impact to patient outcomes, we must be able to target three categories of cells within the tumor: (i) cells sensitive to radiotherapy and chemotherapy; (ii) cells resistant to chemotherapy and (iii) cancer stem-like cells that are able to avoid immune detection and continue seeding tumor persistence.

Our gamma-delta T cell technology has the potential to be a more durable therapy due to limited resistance mechanisms developing in response to it. By combining our INB-200 and INB-400 therapeutic candidate concurrently with alkylating chemotherapies, our approach can promote the upregulation of stress ligands across all three of these categories, making the GBM cells identifiable by our DeltEx DRI cells. CAR-T therapies or any targeted therapy that targets a single antigen is prone to loss of efficacy over time as tumor cells lose, downregulate, or shed the tumor target in response to persistent stimulation. Unlike other CAR-T therapies that are reliant on a single tumor target to ensure tumor cell engagement, our technology generates a stressor that upregulates ligands, i.e., NKG2D ligands, that then activate the gamma-delta T cells. These ligands comprise an intrinsic stress mechanism that is upregulated with hypoxia, DNA instability or any condition that generates circumstances that may limit cell viability. Therefore, there is less likelihood of loss of NKG2D ligands as it is impossible to eliminate all stressors that lead to upregulation of NKG2D ligands that activate gamma-delta T cells. Our unique approach seeks to increase tumor antigen density on the surface of tumor cells to drive activation of immune responses and via an antigen that is tumor agnostic. By pairing our therapy with TMZ we are harnessing the ability of TMZ to upregulate multiple NKG2D ligands to ensure the gamma-delta T cells have the appropriate activation signals already in place to maximize their activity.

We also intend to investigate TMZ in combination with other chemotherapies in the future, which may drive this NKG2D expression further. This may be able to drive to deeper antitumor immune responses that could lead to prolonged progression free survival and increased overall survival and would be combinations to assess in future combination studies.

We believe newly diagnosed GBM may be the ideal indication to assess the potential of INB-200 and INB-400 to drive clinical antitumor activity due to the intrinsic role that TMZ plays in its therapy and with the ability to ensure targeted therapeutic delivery to the tumor site. A third-party paper analyzing the impact of pre-conditioning on the TME to enhance solid tumor CAR-T cell therapy indicated that single-antigen targeting CAR-Ts have been hampered by tumor antigen escape, immune suppression, and lack of T cell trafficking. The inability to infiltrate the tumor site was due largely to the trapping of adoptively transferred

cells in first-pass tissues, such as the lung and liver rather than trafficking to the targeted tumor sites. We believe our approach minimizes the risk of tumor antigen escape because TMZ causes the upregulation of cellular stress signals, consisting of multiple polyclonal ligands that can be recognized by the gamma-delta T cell. Furthermore, our DeltEx DRI approach in newly diagnosed GBM was specifically designed to overcome challenges of systemic T cell localization. The administration of DeltEx DRI cells in INB-200 and INB-400, through an intracranial catheter, directly to the tumor resection site ensures access of the cells to the tumor site and may increase the effector to target, or E:T ratio, and permits localizing the therapy to the specific target area, improving the antitumor activity of cell therapies over intravenous delivery. In the past, other novel modalities, such as treatment with adeno-associated virus, or siRNAs, demonstrated early clinical response by also targeting locally deliverable organ systems such as the eye or liver. Newly diagnosed GBM patients have a more intact immune system that does not have the immune suppression resulting from multiple rounds of earlier chemotherapy and/or radiation as do relapsed populations in whom the CAR-T therapies have been assessed. All immune therapies require an adequate baseline immune activity to maximize their effect. Hence, introducing this therapy in a newly diagnosed population may ensure that the patients have more robust immune systems available to fully mobilize upon tumor cell destruction caused by gamma-delta cell therapy.

INB-200 — Phase 1 Clinical Trial

We are conducting an investigator-initiated Phase 1 repeat dose escalation trial of INB-200 at UAB. We expect this trial to enroll up to 21 patients evaluable for dose-limiting toxicity with newly diagnosed GBM who have completed standard induction therapy with TMZ chemotherapy and radiotherapy and are eligible to initiate maintenance therapy with TMZ.

The primary endpoint of this trial is to assess the safety and tolerability of expanded and activated autologous MGMT genetically modified gamma-delta T cell infusion. Safety will be assessed with single and multiple infusions of 1x107 DeltEx DRI gamma-delta T cells administered through a fenestrated intracranial catheter placed in the resection cavity of the tumor. Secondary endpoints include overall survival, time to progression and response. We also assess biologic activity, including serum and cellular cytokines, immune cell composition, biomarkers, and cell-free DNA both peripherally and from the cerebral spinal fluid, if available. This clinical strategy takes advantage of maximizing gamma-delta T cell cytotoxicity by administering it along with TMZ chemotherapy. The tumor is experiencing maximum stress, increased immunogenicity and expressing high levels of NKG2D ligands required to stimulate the gamma-delta T cells as a result of treatment with TMZ. Further, the natural lymphodepletion achieved by standard of care TMZ ensures that the chemo-resistant gamma-delta cells remain enriched in the vicinity of tumor to eliminate or slow growth of residual tumor.

Eligible patients receive standard-of-care therapy, which includes surgical resection of the GBM tumor, post-surgical induction TMZ and radiation therapy, followed by maintenance TMZ in combination with INB-200, as shown in Figure 10 below. During resection, an intracranial catheter (Rickham catheter) is placed for injection of the INB-200 product. Blood cells for genetic modification are taken from the patient by leukapheresis several weeks following resection, after the patient’s immune system has been allowed to recover from the immunosuppressive environment created by resident tumor. Gamma-delta T cells are then isolated, genetically modified and expanded into the INB-200 product candidate, and then cryopreserved. No more than six weeks post-surgery, patients are treated with induction therapy consisting of daily radiation and TMZ for six weeks followed by a four-week break. Following the four-week period, corticosteroid use is usually tapered, and the patient begins a maintenance phase of TMZ for the first five days of each 28-day cycle for up to six cycles.

INB-400 (Autologous and Allogeneic): Phase 2 Clinical Trials

INB-400 is being designed to assess the relative risk-benefit ratio of allogeneic versus autologously derived genetically modified gamma-delta T cells for treatment patients with GBM, including patients with newly diagnosed GBM and will also assess the activity of allogeneic cells in the relapsed setting. The INB-400 trials are expected to have three cohorts; Arms A, B and C (as represented in Figure 9 below).

Figure 9. Proposed Clinical Trial Design for INB-400

One cohort consisting of INB-400, will further develop the safety and efficacy profile of autologously delivered modified gamma-delta T cells administered to patients with newly diagnosed GBM. In addition, we will generate initial safety data on the INB-400 DeltEx DRI allogeneic cells administered to relapsed GBM patients (Phase 1b). If the initial safety cohort establishes the safety of this modality, two cohorts of patients with either relapsed disease (Arm B) or newly diagnosed disease (Arm C) will receive allogeneic gamma-delta cells. The primary goal of this trial is threefold; (1), to establish the safety of allogeneic, genetically modified gamma-delta T cells; (2) to assess the efficacy of these cells in treating patients with relapsed GBM; and (3) to assess the relative benefit and risk of treating newly diagnosed GBM patients with either allogeneic or autologous genetically modified gamma-delta T cells. While an allogeneic product derived from a healthy and possibly younger individual is likely to have more direct anti-tumor cytotoxicity, the clinical activity noted with the autologous product needs further elaboration and validation. Additional value of an autologous product also lies in the paucity of allogeneic donors for all patients, the potential for greater cell persistence and potential cross talk between cell types leading to additional activity from the activation of bystander cells. Given our experience with INB-100 and the available preclinical data, we expect a low rate of GvHD with the allogeneic product but given the novelty of intracranial delivery of allogeneic cells, the company intends to mitigate risk by also continuing development of the autologous product which appears to have manageable safety while providing evidence of clinical activity. We submitted an IND (INB-400) for the autologous drug product in late 2022, for which clearance was received within the initial 30-day review period by the FDA. We have initiated enrollment of Arm A at multiple centers across the United States. With additional funding, we currently expect to submit a supplemental IND supporting the allogeneic drug product arm in 2025.

Figure 10. INB-200 and INB-400 Administration Protocol

The decision to combine INB-200 and INB-400 in the newly diagnosed GBM setting as an adjunct to standard-of-care therapy was driven by biology, data, and the desire to overcome challenges as outlined above. In this trial, we seek to attack any residual tumor cells when they are most vulnerable with immune cells that are as healthy as possible. By combining INB-200 and INB-400 with maintenance TMZ, we hope to deepen responses achieved by induction chemoradiation by further eliminating residual tumor and driving prolonged immune responses. In addition, introducing gamma-delta T cells in a newly diagnosed population of patients ensures that these patients’ immune systems are as robust and active as feasible to take advantage of tumor elimination created by the gamma-delta T cells. Patients are dosed with INB-200 and INB-400 via intracranial catheter injection, as shown in Figure 10 above, within four hours of receiving intravenous dosing with TMZ on day one of the maintenance cycle. Standard-of-care oral dosing of TMZ will continue for the four subsequent days during each 28-day treatment cycle, as shown in Figure 11 below. Depending on which dose cohort they are enrolled in, patients will be administered either one, three or six injections of INB-200 and INB-400.

Figure 11. Treatment and Manufacturing Timeline of the INB-200 Phase 1 Trial

In 2023, we provided multiple clinical updates for INB-200 including an oral presentation at the ASCO Annual Meeting 2023 and, most recently, a poster presentation at the 2023 SNO Annual Meeting. At SNO, we indicated that twenty-two patients with newly diagnosed GBM have been enrolled in this trial and a total of 10 patients have received treatment as of October 20, 2023. All Cohorts have completed enrollment as of December 31, 2023 and Cohort 3 remains on-going with multiple patients undergoing dosing and continuing to be monitored. No infusion reactions, CRS, neurotoxicity, or other dose limiting toxicities, or DLTs, or treatment-related series adverse events, or SAEs, or treatment-emergent adverse events, or AEs, were observed in Cohorts 1 or 2 to date, or in the three of five Cohort 3 patients who have been dosed as of the October 20, 2023 cut-off date. The patients in Cohort 1 each received a single dose of INB-200, following a minimum of 30 days for safety observation.

The three patients comprising the first dose cohort received a single dose of INB-200, and all patients have died, one due to infection from a pancreatic cyst and two due to progression of disease. Two patients remained alive through 15.6- and 17.7-months post-treatment, having exceeded both their expected progression free survival, or PFS, and overall survival, or OS, respectively. In Cohort 2, four patients have been dosed, with one who remains alive and progression free at 28.5 months, a second patient remained progression free for 22.2 months and is alive at 24.5 months, while a third died without relapse due to a non-treatment-related AE of pulmonary embolus at 8.7 months. As previously disclosed, the first Cohort 2 patient died of an acute cardio-pulmonary event 22 days after receiving their second infusion, which was deemed unrelated to treatment with INB-200 and also died without evidence of disease. The two surviving patients continue to exceed the median survival for GBM patients with the standard Stupp regimen, suggesting that increasing doses of gamma-delta T cells may favor longer PFS and OS. One Cohort 3 patient completed five of six planned doses without any DLTs. The patient had no local GBM relapse, which is typical in 99% of GBM cases, but died of progression with evidence of distal leptomeningeal and peripheral disease, which occurs in approximately 0.4% of patients. Two additional patients remain in dosing in Cohort 3 with an additional two patients awaiting dose initiation.

Following treatment, all patients will be monitored for biologic correlates, time to disease progression and overall survival. The most common AEs were Grade 1/2 events including fatigue, asthenia, urinary tract infection, nausea, headache, platelet and white blood cell count decreased, balance disorders, headache, decreased appetite, hydrocephalus, attributable to TMZ, radiotherapy or disease. One subject had Grade 3 treatment unrelated AEs of urinary tract infection, dehydration, and thrombocytopenia. There were no treatment related deaths, any reports immune effector cell-associated neurotoxicity syndrome, or ICANs, or CRS and repeat dosing has not changed the toxicity profile of this agent as of March 14, 2024.

Figure 12. Summary of Patients Enrolled in INB-200 Phase 1 Trial

Figure 12 above depicts treatment outcomes for patients treated as of October 20, 2023. Early data demonstrate that patients have exceeded expected progression free survival based on their age and tumor MGMT status and have exceeded the median progression free survival predicted of this patient population. In one patient (001), we have histopathology from paired biopsies at first diagnoses (A) and upon relapse (B) 148 days after a single dose of DeltEx DRI gamma-delta T cells in Figure 12 above. These data are matched with peripheral lymphocyte analysis conducted by flow cytometry which demonstrates significant lymphodepletion from the standard-of-care TMZ regimen. Histopathological analysis demonstrated few infiltrating lymphocytes, including gamma-delta T cells within the tumor microenvironment at "A.” At “B,”, a time period when peripheral lymphocyte counts were depleted, significant lymphocytes including alpha-beta T cells, B cells, NK cells and gamma-delta T cells could be found within the tumor microenvironment. Greater than 60% of the tumor tissue was found to be dead necrotic tumor cells and staining for gamma-delta T cells (brown) demonstrated significant infiltration and persistence despite six cycles of monthly TMZ.

Figure 13. T Cells Infiltrating and Persisting in Tumor Tissue

We have completed enrollment of Cohort 3 and we expect to provide clinical updates at medical meetings throughout 2024 and long-term follow-up in 2025.

INB-200 — Preclinical Studies in GBM

Malignant high-grade GBM in both humans and mice express stress ligands that are known to activate NKG2D and are targets for gamma-delta T cell attack. In preclinical testing, gamma-delta T cells exhibited strong cytotoxic activity against several GBM cell lines and primary explant cultures. Normal human brain cells do not express these stress ligands and are not affected.

To assess the antitumor activity of exogenous gamma-delta T cells in GBM as an initial proof-of-concept, it was observed that ex vivo-expanded and activated human gamma-delta T cells prevented emergence of tumors in a U251 GBM model in immunocompromised mice, leading to increased overall survival.

In immunocompetent mice, we found that implantation of GL261 GBM cell line tumors led to a significant increase in levels of endogenous gamma-delta T cells, however these levels decreased over time coincident with tumor progression. Previous clinical studies in GBM and in extracranial malignancies have shown that this decrease is likely a result of T cell exhaustion due to their continuous stimulation by a large and highly aggressive tumor. Indeed, in this study we showed that the increased peripheral blood gamma-delta T cells seen in response to the tumor were already expressing the pre-apoptotic marker Annexin V. Exogenous administration of gamma-delta T cells into the brain immediately after tumor implantation increased overall survival in this model, however these results were not statistically significant.

Improved Antitumor Activity in Combination with Chemotherapy

Based on several years of peer-reviewed and published preclinical work, as well as early human cancer trials, we believe that INB-200 can work in synergy with chemotherapy by causing changes in cancer cells that result in increased expression of activating ligands of gamma-delta T cell and NK cell function, such as NKG2D. In preclinical studies, treatment of TMZ-resistant GBM cells derived from the U87 human GBM cell line with TMZ led to transient increases in a broad panel of stress ligands recognized by the NKG2D receptor, as shown in Figure 14 below.

Figure 14. Increased NKG2D Ligand Expression Observed on TMZ-Resistant Tumor Cells Treated with TMZ

As shown in Figure 15 below, additional studies in glioma cells have demonstrated that NKG2D ligands are also expressed on cancer stem cells, considered as cells that express factors, such as Klf-4, Oct-4, Sox-2, Nanog and Musashi-1. Treatment with TMZ demonstrated that NKG2D ligand expression can also be upregulated several fold on GBM stem-like cells, as depicted in Figure 16 below. This increase in stress ligand expression, even in TMZ-resistant and stem-like cancer cells, has the potential to increase the vulnerability of tumor cells to gamma-delta T cell targeting during the period of pharmacokinetic activity of TMZ.

Figure 15. Cancer Stem-Like Cells Co-Express Stem-Cell Markers and NKG2D Ligands

Figure 16. Increased NKG2D Ligand Expression in Glioma Stem Cells Treated with TMZ

There are two principal challenges to clinical application of TMZ treatment in conjunction with gamma-delta T cells:

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TMZ is cytotoxic to immune cells, including gamma-delta T cells; and

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the increased expression of stress ligands is transient due to resistance mechanisms of the tumor.

Therefore, we believe the ideal gamma-delta T cell exposure would occur when TMZ is still pharmacokinetically active. We developed INB-200 in a way that could enable it to overcome both of these challenges by engineering the cells that make up INB-200 to be resistant to TMZ, an approach we refer to as DeltEx DRI. Treatment of GBM using TMZ increases the levels of NKG2D stress ligands expressed on the tumor cells leading to activation of INB-200. The introduction of the drug-resistant genes is designed to allow INB-200 to survive even when it is administered while TMZ is present even in concentrations above the clinical range. As depicted in in Figure 17 below, concurrent treatment with TMZ causes the direct killing of some tumor cells and immunosuppressive cells while activating gamma-delta T cells, which could lead to stimulating the antitumor activity of INB-200.

Figure 17. DeltEx DRI Mechanism of Action Targeting the DNA Damage Response (DDR)

We have developed a process to genetically modify gamma-delta T cells in order to add a gene that codes for MGMT production. MGMT, a primary DNA repair protein, prevents cell death by repairing the DNA double-stranded breaks caused by alkylating chemotherapy, such as TMZ. As shown in Figure 18 below, introduction of the gene encoding MGMT into gamma-delta T cells using a lentiviral vector decreased the sensitivity of these modified gamma-delta T cells to TMZ by approximately six-fold. A concentration of 63 micromolar, or μM, of TMZ inhibited the proliferation of unaltered gamma-delta T cells by 50%, whereas a concentration of 383 μM of TMZ was required to have a similar effect in DeltEx DRI gamma-delta T cells. We observed that this gene modification did not alter other properties of these gamma-delta T cells, including their cytotoxicity against target cells.

Figure 18. MGMT-Modified Gamma-Delta T Cells Demonstrate Protection Against Killing Effects of TMZ

Our preclinical studies supporting the clinical development of DRI and the submission of an IND to the FDA was peer-reviewed and published online in the Nature portfolio journal Scientific Reports in October 2021. In preclinical studies of INB-200 in GBM patient-derived xenograft models, we observed that the combined dosing of TMZ and treatment with our DeltEx DRI gamma-delta T cells led to a statistically significant (p-value ≤ 0.05) increase in overall survival in primary GBM xenograft tumors, as compared to mice treated separately with either chemotherapy or gamma-delta T cells. Unmodified gamma-delta cells showed no survival benefit. Subsequent histopathological analysis demonstrated no visible residual tumors in INB-200-treated animals at 150 days, as shown in Figure 20 below. This is important since xenograft models convey the heterogeneity of a human-derived tumor and not the monotonous population of a cell line used in syngeneic models. Separately, we also examined the potential for sequencing chemotherapy and cell therapy, separating gamma-delta T cells from TMZ therapy by 24 hours (condition 1) and outside the effective concentration of TMZ. As shown in Figure 19 below, we observed that in TMZ-sensitive tumors treated with the sequenced regimen, delivery of the DeltEx DRI gamma-delta T cells led to modest improvement in median overall survival of 75 days compared to 60 days with TMZ alone but with no overall survival benefit over TMZ. Conversely, as discussed above, the combined and concomitant delivery of TMZ and DeltEx DRI gamma-delta T cell regimen (condition 2) resulted in 80% of mice surviving beyond 150 days. These results are consistent with our observations in cell lines, in which we observed that treatment with TMZ led to transient increase in the levels of NKG2D stress ligands. We believe the increased expression of these stress ligands, in turn, led to increased cytotoxic activity of the DeltEx DRI gamma-delta T cells. In preclinical studies, we observed that, even in TMZ-resistant tumors, administration of MGMT-modified gamma-delta T cells led to an increase in median and overall survival while sequencing TMZ and gamma-delta T cells showed no benefit.

Figure 19. Improved Survival Observed in Both TMZ-Sensitive and TMZ-Resistant GBM Models

Figure 20. Histopathology Demonstrates No Residual GBM in Mice

These preclinical results are supported by observations of gamma-delta T cells in human cancer patients. As shown in Figure 21 below, in 2011, a group in Japan published results of an early clinical trial testing the adoptive transfer of ex vivo-expanded autologous gamma-delta T cells for the treatment of advanced solid tumors in the British Journal of Cancer. The paper discusses the need to evaluate combinations of gamma-delta T cell therapies with other therapies and how to appropriately time administration of such combination therapies to generate synergy and avoid damage to gamma-delta T cells. However, while no dose limiting toxicity was observed, most patients progressed, with progressive disease (n=12) or stable disease (n=3) being the predominant tumor responses reported. Three patients who were receiving other therapies and were progressing or considered unlikely to respond to standard therapy received gamma-delta T cells in parallel. All three patients demonstrated tumor responses with two partial remissions and one complete remission.

Figure 21. Treatment and Clinical Outcomes for Ex Vivo Expansion of Vg9Vd2 T Cells

INB-200 for Other Oncology Indications and Use in Combination with Other Therapies

As we look to expand the potential applications for INB-200, we are evaluating its antitumor activity in other tumors commonly treated with TMZ or other alkylating agents such as dacarbazine or the nitrosoureas. These tumors may include additional brain tumors, melanoma, uveal melanoma, neuroendocrine and adrenal tumors, soft tissue sarcomas, uterine sarcoma, small cell lung cancer, and ovarian cancer, among others.

Based on extensive preclinical data, we also intend to investigate the potential combination of drug resistant gamma-delta T cells with other immuno-oncology drugs, such as checkpoint inhibitors, which may enhance the immunostimulatory activity of these cells. We also plan to assess other mechanisms of chemotherapy resistance and the potential of combinations of drug-resistant gamma-delta T cells with inhibitors of DNA damage repair proteins, such as PARPi that have been shown to increase the expression of stress signals such as NKG2D ligand expression in tumor cells as described above. Consistent with our previous work, we anticipate that this significant increase in stress signaling may improve the ability of gamma-delta T cells to target these tumors.

INB-100 for the Treatment of Patients with Hematological Malignancies Undergoing HSCT

INB-100 is an allogeneic DeltEx product candidate created from healthy donors. The INB-100 product consists of allogeneic, expanded activated gamma-delta T cells. We are developing INB-100 for the treatment of patients with hematological malignancies that are undergoing haploidentical, matched-related HSCT. We are collaborating with Joseph McGuirk, D.O. at the University of Kansas Cancer Center, to conduct an investigator-initiated Phase 1 dose escalation clinical trial of INB-100 to assess the safety and tolerability of INB-100. An expansion cohort of an additional 10 patients is underway at the RP2D. As of the November 3, 2023 cut-off date for the update provided at the 2023 American Society of Clinical Oncology, or ASH Annual Meeting, we have treated 10 patients in this trial with all 10 patients remaining in morphologic complete remission, or CR, including six patients for periods greater than one year, of which two patients for periods greater than three years, one patient for a period greater than two years.

Hematological Malignancies Overview

Hematological malignancies are characterized by an abnormal and excessive proliferation of malignant hematopoietic cells in the marrow. In some patients, these cancerous cells proliferate rapidly, requiring urgent treatment. These include AML, ALL, chronic myeloid leukemia in blast phase and myelodysplastic syndromes, or MDS. There are few curative treatment options for these patients once they have progressed on standard-of-care first line therapies. One of the most effective is allogeneic HSCT, where the patient’s blood forming cells, including cancerous cells, are first destroyed using chemotherapy, radiation or a combination of both. The patient then receives new bone marrow stem cells from a healthy donor to repopulate their hematopoietic system.

Allogeneic Hematopoietic Stem Cell Transplantation Overview

HSCTs are generally for patients with various hematological malignancies where additional therapy can lead to longer-term durability and survival. As depicted in Figure 22 below, the number of HSCT procedures has been increasing over the last 20 years, with more than 8,000 patients treated in the United States in 2021.

The challenge facing many patients who are in need of an allogeneic HSCT is the identification of an appropriately matched donor. Histocompatibility, or tissue compatibility, is the property of having the same, or sufficiently similar, alleles of a set of genes called human leukocyte antigens, or HLAs, between a donor and recipient. Differences in histocompatibility and other tissue antigens between the host and the transfused donor-derived alpha-beta T cells can trigger a series of potentially life-threatening consequences, such as GvHD. While immunosuppressive drugs can help reduce GvHD, they are not always successful, and their long-term use is associated with multiple complications including infection and may ultimately fail to prevent leukemic relapse. A match of 8/8 HLA alleles is considered fully matched and is associated with the lowest frequency of GvHD.

Figure 22. Number of Allogeneic HCTs in the US by Donor Type

In some cases, a donor can be identified who is a close relative and in other cases it may be someone who volunteered to be included in a national donor registry. Because of underrepresentation of the HLA alleles found in many ethnic groups, the probability of identifying a donor with a full match varies widely. Up to 75% of patients of White European descent can find a donor with a full match, but that number drops to 19% for African American patients. Patients who cannot find a fully matched donor must either accept a non-ideal match, which is associated with a higher risk of GvHD, or forgo HSCT entirely. Haploidentical, or partially matched donors, who are relatives, that share alleles with the transplant recipient provide one option for patients lacking a matched donor and are the fastest growing type of HSCT in the U.S.

Our Solution — INB-100 for the Treatment of Patients with Hematological Malignancies Undergoing HSCT

We are developing INB-100, an expanded and activated gamma-delta T cell product, with the goal of testing the safety of allogeneic gamma-delta T cells and improving overall survival in patients with hematological malignancies who have undergone allogeneic HSCT. We believe that supplementing the patient’s immune system with allogeneic gamma-delta T cells will lead to reduced incidence of relapse and improved survival in these patients.

Multiple retrospective studies of leukemia patients treated with alpha-beta TCD allogeneic HSCT showed that high levels of gamma-delta T cells were associated with a significantly higher rate of disease-free survival. In a foundational study led by Dr. Lamb, patients with high levels of gamma-delta T cells had a disease-free survival rate at seven years of over 70% compared to less than 20% for patients with low levels of gamma-delta T cells, which has been supported by subsequent studies. The majority of this effect was observed within six months of treatment. The primary cause of death for patients with low or normal levels of gamma-delta T cells was leukemic relapse. Often, leukemic relapse is due to a loss of MHC in any residual cancerous cells and gamma-delta T cells may offer a solution as their killing through stress signaling is independent of MHC. Approximately 60% of the patients with elevated gamma-delta T cells who relapsed were still surviving at the time of the publication compared to only 2%, or one patient, with low levels of gamma-delta T cells.

To produce INB-100, we developed a functionally closed manufacturing process that is designed to routinely and cost effectively generate the quantities of the cells required for the treatment of patients. Initially we utilized the manufacturing facility at the University of Kansas Cancer Center, the site of our Phase 1 dose-escalation trial with INB-100. We have since shifted our manufacturing to the GMP facility at UAB, in which we have contracted access for several years, to streamline the process and centralize manufacturing. We have implemented manufacturing process improvements which were included in recent IND modifications that we believe could substantially increase the yield and the number of gamma-delta T cells.

Phase 1 Clinical Trial of INB-100

We are conducting an investigator-initiated Phase 1 dose escalation trial of INB-100 in patients with hematologic malignancies who are undergoing allogeneic haploidentical HSCT. The primary endpoints of this trial are safety and tolerability, and secondary endpoints include rates of acute and chronic GvHD, relapse rate and overall survival. Following completion of the dose escalation phase in 2023, a decision was made to declare dose level 2 our RP2D and expand enrollment with an additional 10 patients at the dose level.

INB-100 is prepared from donor peripheral blood cells, while in parallel, patients undergo HSCT using donor bone marrow. INB-100 cells are administered post-engraftment with the goal of providing immunity during the period of immune cell reconstitution and long-term residual gamma-delta T cells that can scavenge any residual leukemic cells that may remain.

Figure 23. INB-100 Administration

As depicted in Figure 23 above, patients are initially treated using a standard HSCT protocol, originally developed at Johns Hopkins University, or the Hopkins protocol, under which these patients undergo non-myeloablative reduced intensity conditioning regimen using chemotherapeutic agents that destroy their tumor cells as well as their healthy immune cells and post-transplant cyclophosphamide to reduce GvHD. They then undergo allogeneic bone marrow transplant. Prior to the bone marrow transplant, donors undergo leukapheresis to provide the starting material for INB-100 at least seven days prior to transplant. The INB-100 starting material will then be prepared and cryopreserved. After approximately 15 to 20 days, hematopoietic stem cells from the donor engraft in the patient’s bone marrow and begin reconstituting the immune system. While the Hopkins protocol has decreased the risk of GvHD, there is also a reduced anti-leukemic effect. Accordingly, the rate of leukemic relapse is approximately 51% at one year and even greater in those patients with high-risk and/or complex cytogenetics. More recent data presented at ASH 2023 in a 2200 patient study by the EBMT demonstrates that leukemic relapse in AML patients receiving haploidentical stem cell transplantation with post-transplant cyclophosphamide continues to fall between 40-50%. Within five days of neutrophil engraftment, our INB-100 product candidate will be thawed and administered as a single weight-based dose, leading to an increase in the levels of gamma-delta T cells and potentially providing greater anti-leukemic effect and delaying relapse.

As represented in Figure 24 below, as of November 3, 2023, 14 patients have been enrolled in this trial. Ten subjects were dosed with INB-100 our Allogeneic therapeutic candidate and one subject (Patient 001) died prior to receiving INB-100 due to cardiogenic shock most likely from post-HSCT cyclophosphamide while two others were unable to be treated due to an inability to generate adequate product. One patient was dosed with a suboptimal dose of cells and not considered evaluable for safety or efficacy but has been the only patient who received any INB-100 who has relapsed and/or died to date. One subject relapsed prior to dosing and was deemed a screen failure. All patients remain in morphologic CR with six of the 10 now relapse free for over 12 months. The four patients treated in Cohort 1 demonstrated that allogeneic gamma-delta T cell therapy has a manageable toxicity profile with the potential for durable remissions in high-risk patients with those patients remaining relapse free at 42.7, 40.3, 28.6 and 14.3 months respectively. Of the six Cohort 2 patients dosed at 3x106 cells/kg, two remain relapse-free at 12.2 and 12.0 months and the remainder are relapse free at 4.9-9 months as of the data cut off above. Notably, at the 2023 ASH Annual Meeting held in December 2023, data demonstrated that patients in both Cohorts 1 and 2 had in vivo expansion and persistence of gamma-delta T cells that resulted in elevated gamma delta T cell levels up to 1-year post-transplant.

INB-100 continues to demonstrate a manageable safety profile to-date, with no dose-limiting toxicities, no treatment-related Grade 3 or greater adverse events, and no CRS, or ICANS. All patients have sustained steroid responsive Grade 2 skin GvHD while three patients reported Grade 2 gastrointestinal GvHD that resolved with steroid therapy. No events of Grade 3 or greater GvHD, CRS or ICANS has been observed. Three patients have reported mild chronic GVHD in Cohort 1.

We expect to complete enrollment of the expansion cohort of this Phase 1 clinical trial in 2024, with updated results to be presented at medical meetings throughout 2024 and topline results to be released in 2025.

Figure 24. Summary of Patients Treated in INB-100 Phase 1 Trial

INB-100 Preclinical Studies

Animal studies and indirect evidence from human allogeneic transplant studies suggest that gamma-delta T cells can facilitate engraftment, which may translate into faster reconstitution of the immune system. In a murine allogeneic transplant model, donor gamma-delta T cells facilitated the engraftment of TCD donor bone marrow. When TCD donor marrow was supplemented with up to 3x106 gamma-delta T cells prior to infusion into mismatched recipients, donor chimerism increased by approximately 40%. A separate study revealed similar findings in MHC-mismatched mice, and later demonstrated that the gamma-delta T cell dose necessary to facilitate engraftment did not result in lethal murine GvHD. Improved engraftment was also observed in lethally irradiated rats reconstituted with 1x108 alpha-beta T cell depleted bone marrow, suggesting that gamma-delta T cells are able to facilitate improved engraftment even in the absence of alpha-beta T cells. In this study, all rats engrafted with a mean of 92% (± 4%) donor cells and showed no clinical evidence of GvHD. Studies comparing patients who received alpha-beta TCD grafts with those receiving pan-TCD grafts also show a positive association between the number of gamma-delta T cells in the graft and less time to engraftment.

Both murine and human studies suggest that gamma-delta T cells are not primary initiators of GvHD and may in fact modulate the GvHD activity of alpha-beta T cells. Indeed, large doses of expanded gamma-delta T cells have been infused into lethally irradiated MHC-disparate mice without causing GvHD. Although it has been observed that gamma-delta T cells have activated GvHD response, the investigators reporting this study found no direct evidence that GvHD was initiated by gamma-delta T cells. In two separate human trials, it was observed that gamma-delta T cells were not substantially activated in the in vitro allogeneic mixed lymphocyte culture. Several studies post-HSCT have shown transient increases in gamma-delta T cells,

but have not associated this finding with GvHD. Studies comparing outcomes of patients that received alpha-beta T cell depleted grafts with pan-T cell depleted grafts all showed a lower incidence of GvHD in the alpha-beta T cell depleted group, suggesting that infusion of gamma-delta T cells in the graft does not subject the recipient to increased risk of GvHD. Whether gamma-delta T cells are truly less likely to contribute to the development of GvHD or the contribution of any residual alpha-beta T cells in the graft remains untested. However, from the above reasoning, it is logical to propose that in future studies, gamma-delta T cells might indeed be introduced in the setting of allogeneic HSCT, specifically to provide innate anti-tumor effect with only minimal risk of GvHD.

Future Development for Our Lead Product Candidates

Our goal is to ultimately treat solid tumor cancers with an allogeneic cellular immunotherapy. Delivering a previously manufactured and cryopreserved therapeutic product from donor to patient could have the ability to create a product that is produced and sold as “off-the-shelf.” We believe this could improve the availability of cell therapy products, as well as potentially reduce the cost of the product to both us and to the patients. Ultimately a donor-derived product may be superior to a patient-derived product, as cells can be harvested and manufactured from younger, healthy individuals who do not have a potentially immune-suppressive tumor impacting the function of their immune cells. The goal of an allogeneic delivered product for solid tumor cancers is complex and we are not aware of any solid tumor cancers currently treated with transplant or lymphodepletion protocols.

The necessity to add transplant and lymphodepletion protocols increases the complexity of treatment due to the risk of potentially fatal GvHD from HLA-mismatched cells in the solid tumor setting. Further, this may also bring to question the direct impact of the lymphodepleting regimen such as flu/cy on the tumor itself. In our INB-200 and INB-400 programs for GBM, the standard-of-care chemotherapy with TMZ is our lymphodepleting regimen and has been in use in this setting for over 18 years.

To reach our goal of advancing toward an allogeneic genetically modified product candidate for solid tumors, we are currently pursuing two ongoing Phase 1 clinical trials that could provide the data required for applicable regulatory filings. INB-100 is an unmodified, allogeneic product candidate tested in the transplant setting, results from which will help assess the risk of GvHD from HLA-mismatched gamma-delta T cells, or potentially any residual alpha-beta T cells that may remain. INB-200 is an autologous, genetically modified gamma-delta T cell product candidate that tests the safety and efficacy of our DRI approach in our first solid tumor indication. Our goal is to combine the prior safety data from both of the ongoing clinical trials for INB-200 and INB-100 in order to create the regulatory package for the allogeneic-sourced product arm of INB-400 for the treatment of GBM and other solid tumor cancers.

Our Additional Product Candidates

INB-300: Non-Signaling CAR Gamma-Delta T Cells

INB-300 is our DeltEx nsCAR gamma-delta T cell preclinical product candidates that combine our expertise in gamma-delta T cells and a novel CAR directed against novel antigen targets. While we have developed a classical signaling CAR-T construct which is cytotoxic, we have also designed novel nsCAR constructs that omit the CD3z signaling domain. This nsCAR allows the modified gamma-delta cells to better traffic to the tumor cells expressing an antigen targeting receptor but maintains their endogenous receptors that recognize cellular stress ligands. This enables the cells to utilize their full range of antitumor killing receptors to recognize and kill tumor cells, rather than over-riding these functions and restricting them to recognizing a single antigen transmitted through the CAR, which is typical in a classical signaling CAR. This non-signaling strategy also incorporates a significant safety advantage in that off-target CAR binding of cells that are not expressing high levels of NKG2D or TCR antigens, i.e., healthy normal tissue, would not result in activated cell killing and thus avoid an unintended cytotoxic response as shown in Figure 25 below, published in the Nature.com article “T cells without limitation” in March 2023.

Additionally, this CAR construct can also incorporate the gene for MGMT from our DeltEx DRI candidate or designed to also secrete cytokines such as IL-15. Thus, such nsCAR constructs can be designed to confer chemotherapy-resistance, cytokine secretion and tumor-targeting capability to transduce gamma-delta T cells. Early data show that our new constructs are capable of serial killing of cancer cells, generated synergies with significantly greater CD69 activation than expected from the activity of a single antigen binding domain as well as increased persistence.

Figure 25. INB-300, a DeltEx Non-Signaling CAR Constructs

To date, we have created nsCAR constructs against antigens, including the peptide chlorotoxin, or CLTX, which is expressed on GBM and other solid tumors, and the leukemia antigen targets CD19 and CD33. Early proof-of-concept data demonstrating the ability of our nsCAR constructs to distinguish between tumors and healthy tissue were presented at the AACR Annual Meeting in 2023 and at our R&D Day in October 2023. The nsCAR platform has demonstrated a greater than 15x difference in killing between leukemic cells and healthy B cells (effector to target, or E:T, ratio=2:1, 79.7% versus 5.2%) when both express the CD19 target antigen. At our R&D Day we presented the initial data of an nsCAR targeting CD33 and co-expressing IL-15 for AML (Figure 26). Initial cytotoxicity data demonstrated ns33CAR+IL-15 killing of approximately 3% against CD34+ hematopoietic progenitor cells, or HPCs versus an average of approximately 65% killing against three separate AML cell lines at an E:T ratio of 8:1. We expect to provide additional preclinical updates on this program at the 2024 AACR conference in April 2024.

Figure 26. INB-300 – ns33CAR+IL15 γδ T vs. Leukemias: Normalized Results

INB-500: Induced Pluripotent Stem Cell (iPSC) Derived Gamma-Delta T cells

In May 2022, we unveiled the expansion of our DeltEx platform capabilities to include induced pluripotent stem cell derived gamma-delta T cells. iPSCs represent a significant step toward next generation approaches of cellular manufacturing for true allogeneic and potentially ‘off-the-shelf‘ innate cell therapies. Allogeneic cell therapies offer two distinct and mutually exclusive potential benefits: (i) the ability to treat a cancer patient with cells derived from a younger, healthy individual that likely has greater killing ability, or cytotoxicity, and (ii) the potential ability to replicate multiple billions of cells to treat multiple patients from a single clone derived from a single donor that can be stored and delivered “off-the-shelf.” We are testing these potential benefits separately. While our INB-100 program will test and compare the activity of autologous versus allogeneic cells, there remain limits to the expansion capabilities of primary derived gamma-delta T cells due to telomere shortening with every replication cycle. To overcome these limits, we have advanced INB-500, our gamma-delta T cell program based on cells derived from iPSCs.

Cell expansion and therapeutic doses are generally limited by total starting cell count available from a donor, body mass of the recipient, T cell exhaustion during expansion, biologic replication limits due to the Hayflick phenomenon and telomere shortening and limits imposed by regulators due to the potential for cellular transformation. Pharmaceutical guidelines exist to track in vitro cell age as there are phenotypic and genotypic changes that occur with increasing cellular passages and population doubling cycles. Sponsors are required to establish criteria for an upper limit to population doubling level of cells used for production for clinical use. By re-programing cells into a pluripotent, stem-like state, they gain the potential for near unlimited replication. Such cells can be replicated and subsequently differentiated into specific cell lineages, including gamma-delta T cells. To date, we are one of only two companies to have publicly demonstrated an ability to produce gamma-delta T cells from iPSCs. In addition, we believe we are the only company to have demonstrated the ability to derive both Vdelta1+ and Vdelta2+ gamma-delta T cells from iPSCs. We have demonstrated a reproducible expansion process and the ability to genetically engineer our iPSC derived gamma-delta T cells. iPSC derived gamma-delta T cells enable the ability to genetically edit cells and pick specific clones with nearly 100% of cells expressing the gene of interest and to avoid random insertions and/or deletions that can potentially occur with lentivector transductions. Our processes are cell and serum free, and we continue to further develop our expansion capabilities of each subclone and the characterization of such cells.

License Agreements

Exclusive License Agreement with Emory University, Children’s Healthcare of Atlanta, Inc. and The UAB Research Foundation

In June 2016, we entered into an Exclusive License Agreement with the Emory University, Children’s Healthcare of Atlanta, Inc. and The UAB Research Foundation, or UABRF, as amended from time to time, which we refer to as the Emory license agreement. We amended the Emory license agreement in October 2017 and July 2020. Under the Emory license agreement, we obtained an exclusive worldwide license under certain immunotherapy-related patents and know-how related to gamma-delta T cells developed by the Emory University, Children’s Healthcare of Atlanta, Inc. and UABRF’s affiliate, UAB, to develop, make, have made, use, sell, import and otherwise commercialize products that are covered by such patents or otherwise incorporate or use the licensed technology. Such exclusive license is subject to certain rights retained by these institutions and also the U.S. government.

In consideration of the license granted to us under the Emory license agreement, we paid Emory a nominal upfront payment. We are required to pay Emory development milestones totaling up to an aggregate of $1.4 million, low-single-digit to mid-single-digit tiered running royalties on the net sales of the licensed products, including an annual minimum royalty of $0.5 million beginning in the third year following the first sale of a licensed product, increasing to $1.0 million in the fourth year and $1.5 million in the fifth year and thereafter. In addition, we are also required to pay Emory between 1% and 15% of any fees or payments we may receive from our sublicensees, depending on when the sublicense executed. In the event no milestone payments have been paid in certain years, we will be required to pay an annual license maintenance fee: prior to the 78th-month anniversary of the agreement, $250,000; prior to the 90th-month anniversary of the agreement, $0.5 million; and on or after the eight-year anniversary of the agreement, $1.0 million. The Emory license agreement also requires us to reimburse Emory for the cost of the prosecution and maintenance of the licensed patents.

Pursuant to the Emory license agreement, we are required to use our best efforts to develop, manufacture and commercialize the licensed product, and are obligated to meet certain specified deadlines in the development of the licensed products.

The term of the Emory license agreement will continue until 15 years after the first commercial sale of the licensed product, or the expiration of the relevant licensed patents, whichever is later. We may terminate the Emory license agreement at will at any time upon prior written notice to Emory. Emory has the right to terminate the Emory license agreement if we materially breach the agreement (including failure to meet our diligence obligations) and fail to cure such breach within specified cure period, if we become bankrupt or insolvent or decide to cease development and commercialization of the licensed product, or if we challenge the validity or enforceability of any licensed patents. For more information related to the intellectual property acquired pursuant to the Emory license agreement, see the section titled “Business—Intellectual Property.”

Exclusive License Agreement with UABRF

In March 2016, we entered into an Exclusive License Agreement with UABRF, as amended from time to time, which we refer to as the UABRF license agreement. We amended the UABRF license agreement in December 2016, January 2017, June 2017 and November 2018. Under the UABRF license agreement, we obtained an exclusive worldwide license under certain immunotherapy-related patents related to the use of gamma-delta T cells, certain CAR-T cells and combination treatments for cell therapies developed by UAB and owned by UABRF to develop, make, have made, use, sell, import and otherwise commercialize products that are covered by such patents. Such exclusive license is subject to certain rights retained by UABRF and also the U.S. government.

In consideration of the license granted to us under the UABRF license agreement, we paid UABRF a nominal upfront payment and issued 91,250 shares of our common stock to UABRF, which were subject to certain antidilution rights. The antidilution provision required us to issue additional shares of common stock such that UABRF maintained a 2.5% ownership interest in the company until we raised at least $20.0 million through one or more rounds of investment. As of August 2020, we raised an aggregate of $36.6 million through the sale of our securities. Between March 2017 and August 2020, we issued UABRF an additional 151,382 shares of our common stock in satisfaction of this antidilution provision. Accordingly, beginning in September 2020, the shares held by UABRF may be diluted only upon the same terms and conditions of certain founders until the completion of our initial public offering.

In addition, we are required to pay UABRF development milestones totaling up to an aggregate of $1.4 million, lump sum royalties on cumulative net sales totaling up to an aggregate of $22.5 million, mid-single-digit running royalties on our net sales of the licensed products, low single-digit running royalties on net sales of the licensed products by our sublicensees, and a share of certain non-royalty income ranging between 2.5% to 25%, depending on the status of certain clinical trials, that we may receive, including from any sublicensees. The UABRF license agreement also requires us to reimburse UABRF for the cost of the prosecution and maintenance of the licensed patents.

Pursuant to the UABRF license agreement, we are required to use good faith reasonable commercial efforts to develop, manufacture and commercialize the licensed product.

The term of the UABRF license agreement will continue until the expiration of the licensed patents. We may terminate the UABRF license agreement at will at any time upon prior written notice to UABRF. UABRF has the right to terminate the UABRF license agreement if we materially breach the agreement and fail to cure such breach within a specified cure period, if we fail to diligently undertake development and commercialization activities as set forth in the development and commercialization plan, if we underreport our payment obligations or underpay by more than a specified threshold, if we challenge the validity or enforceability of any licensed patents, or if we become bankrupt or insolvent. For more information related to the intellectual property acquired pursuant to the UABRF license agreement, see the section titled “Business—Intellectual Property.”

Sales and Marketing

Given our stage of development, we have not yet established a commercial organization or distribution capabilities. We plan to build focused capabilities in the United States to commercialize our development programs focused on allogeneic or autologous, genetically modified gamma-delta T cell therapies for the treatment of cancer, where the patient populations and medical specialists for the indications we are targeting are sufficiently concentrated to allow us to effectively promote our products, if approved for commercial sale, with a targeted sales team. In other markets for which commercialization may be less capital efficient for us, we may selectively pursue strategic collaborations with third parties in order to maximize the commercial potential of our product candidates.

Manufacturing

We do not own or operate manufacturing facilities for the production of our current product candidates. We currently rely on third-party contract manufacturers for all of our required raw materials, manufacturing devices, active pharmaceutical ingredients, lentiviral vectors and finished product for our preclinical research and clinical trials. We have agreements with multiple GMP cell therapy labs to manufacture product candidates for our Phase 1 and Phase 2/3 clinical trials. The multi-year agreements allow our medical technologists direct access to the facilities to assist and operate alongside the GMP facility staff. The agreements provide for manufacturing on a per-patient basis. We intend to enter into agreements with third-party manufacturers and/or facilities for future production. We are analyzing the feasibility and costs of building manufacturing capabilities for future development and commercial quantities of any products that we develop. Such products will need to be manufactured in facilities, and by processes, that comply with the requirements of the FDA and the regulatory agencies of other jurisdictions in which we are seeking approval.

Competition

The biotechnology industry is characterized by intense and dynamic competition to develop new technologies and proprietary therapies. Any product candidates that we successfully develop and commercialize will have to compete with existing therapies and new therapies that may become available in the future. We believe that our proprietary gamma-delta T cell platform and our product candidates, strategic collaborations and scientific and clinical expertise may provide us with competitive advantages. However, we face potential competition from various sources, including larger and better-funded pharmaceutical, specialty pharmaceutical and biotechnology companies, as well as from academic institutions, governmental agencies and public and private research institutions. The key competitive factors affecting the success of any product that may be approved by regulators will include the efficacy, safety profile, pricing, method of administration and level of promotional activity.

The field of gamma-delta T cells is growing rapidly. Our known competitors in the field of allogeneic and gamma-delta T cell therapy include Acepodia USA, Adaptimmune Therapeutics plc, Adicet Bio, Inc., Allogene Therapeutics, Inc., American Gene Technologies International Inc., Astellas Pharma US, Inc., Avalon Globocare Corp., Beroni Group Ltd, Century Therapeutics, Inc., Creative Biolabs, CytoMed Therapeutics Pte Ltd, Editas Medicine, Inc., Enochian BioSciences, Inc., Eureka Therapeutics, Inc., Expression Therapeutics, Inc., Gadeta BV, ImCheck Therapeutics SAS, Immatics Biotechnologies GmbH, Johnson & Johnson Innovative Medicine, a division of Johnson & Johnson, Kiromic Biopharma, Inc., LAVA Therapeutics N.V., Leucid Bio Ltd, OneChain Immunotherapeutics, S.L., OverT Bio, Inc., PersonGen BioTherapeutics (Suzhou) Co., Ltd., PhosphoGam Inc., Sandhill Therapeutics, Inc., Shattuck Labs, Inc., Takeda Pharmaceuticals USA, Inc., TC BioPharm Limited, and The Bristol-Myers Squibb Company, several of which have initiated clinical trials. Our gamma-delta T cell product candidates may also compete with other cell and molecule-based immunotherapy approaches using and/or targeting natural killer cells, T cells and dendritic cells.

Many of our current or potential competitors have greater financial resources and infrastructure, including larger research and development staffs, infrastructure to support testing, developing, marketing and commercialization of products. Many of these companies also have more experience in conducting clinical trials, obtaining FDA and other regulatory approvals, and manufacturing, marketing and distributing therapeutic products. Smaller or clinical-stage companies like us may successfully compete by establishing collaborative relationships with larger pharmaceutical companies or academic institutions. Accordingly, our competitors may be more successful than us in obtaining approval for treatments and achieving widespread market acceptance. Our competitors’ treatments may be more effective, or more effectively marketed and sold, than any treatment we may commercialize and they may render our treatments obsolete or non-competitive before we can recover the expenses of developing and commercializing any of our treatments.

Mergers and acquisitions in the biotechnology and pharmaceutical industries may result in even more resources being concentrated among a smaller number of our competitors. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical study sites and subject registration for clinical studies, as well as in acquiring technologies complementary to, or necessary for, our programs. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies.

We anticipate that we will face intense and increasing competition as new therapies enter the market and advanced technologies become available. We expect any treatments that we develop and commercialize to compete on the basis of, among other things, efficacy, safety, convenience of administration and delivery, price, the level of generic competition and the availability of reimbursement from government and other third-party payers.

Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize products that are safer, more effective, have a better safety profile, are more convenient or are less expensive than any products that we may develop. Our competitors also may obtain FDA or other regulatory approval for their products more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we are able to enter the market.

Intellectual Property

Overview

We actively seek to protect our proprietary technology, inventions, improvements to 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 future in-licensing opportunities to develop, strengthen and maintain the strength of our position in the field of gene therapy that may be important for the development of our business. Additional regulatory protection may also be afforded through data exclusivity, market exclusivity and patent-term extensions where available.

As of December 31, 2023, we owned, co-owned or exclusively licensed three issued U.S. patents, five issued European patents, twelve other issued foreign patents, ten pending U.S. applications, one pending PCT application and 49 other foreign national-stage applications, including six European regional-phase applications that are important to the development of our business.

Our policy is to file patent applications to protect proprietary technology, inventions and improvements to inventions and other intellectual property that may be commercially important to the development of our business. We also intend to seek additional patent protection or rely upon trade secret rights to protect other technologies that may be used to manufacture and develop our gamma-delta T cell products. We are a party to exclusive license agreements that grant us rights to use specific technologies in our gamma-delta T cell products and in the manufacturing and development of our products. For more information, see the section titled “Business—License Agreements.”

Our Patent Portfolio

Patent applications directed to our most advanced programs are summarized below.

INB-200

Pursuant to the Emory license agreement, we have licensed two issued U.S. patents, three issued European patents (each which have been widely validated in Europe) and one U.S pending patent application. These patents and applications contain claims or supporting disclosures directed to the INB-200 composition of matter and to methods of treating diseases of interest using INB-200. Issued patents and patents issuing from the pending applications, if any, are expected to expire in 2030, without accounting for potential patent term extensions and adjustments.

INB-200 and Immune Checkpoint Inhibitor Combination Therapy

We co-own one pending U.S. patent application, one issued Japanese patent, one issued Australian patent, one issued New Zealand patent, and eight other national stage patent applications including a European regional phase application with The UAB Research Foundation. These patents and applications contain claims or supporting disclosures directed to methods of treating diseases of interest using INB-200 in combination with immune checkpoint inhibitor therapies. Issued patents and patents issuing from the patent applications, if any, are expected to expire in 2037, without accounting for potential patent term extensions and adjustments.

INB-200 and PARP Inhibitor Combination Therapy

We co-own one pending U.S. patent application and nine other foreign national stage applications with The UAB Research Foundation that contain claims or supporting disclosures directed to methods of treating diseases of interest using INB-200 in combination with PARP inhibitor therapies. Patents issuing from these patent applications, if any, are expected to expire in 2039, without accounting for potential patent term extensions and adjustments.

INB-100

Pursuant to the UABRF license agreement, we have licensed one U.S patent application, one issued Japanese patent, one issued Singaporean patent, one issued Australian patent, and nine foreign national-stage applications, including a European regional phase application. These patents and applications contain claims or supporting disclosures directed to methods of treating diseases of interest using INB-100. Issued patents and patents issuing from these patent applications, if any, are expected to expire in 2036, without accounting for potential patent term extensions and adjustments.

We also own one pending U.S. provisional patent application that contains claims or supporting disclosures directed to additional methods of treating diseases of interest using INB-100.

INB-300

Pursuant to the UABRF license agreement, we have also licensed one issued U.S. patent, one issued Israeli patent, one pending U.S. patent application and ten foreign national-stage applications, including a European regional phase application. These patents and patent applications contain claims or supporting disclosures directed to the INB-300 composition of matter and to methods of treating diseases of interest using INB-300. Issued patents and patents issuing from these patent applications, if any, are expected to expire in 2037, without accounting for potential patent term extensions and adjustments.

We also own one pending U.S. application, six foreign national patent applications that contains claims or supporting disclosures directed to additional INB-300 compositions and to methods of treating diseases of interest. Patents issuing from this patent application, if any, are expected to expire in 2042, without accounting for potential patent term extensions and adjustments.

In addition, we own two pending U.S. provisional patent applications that contains claims or supporting disclosures directed to further INB-300 compositions and to methods of treating diseases of interest.

INB-500

We own one pending PCT application that contains claims and supporting disclosures for methods of generating, producing and genetically modifying iPSC gamma-delta T cells and to methods of use including treating diseases of interest. Patents issuing from this patent application, if any, are expected to expire in 2043, without accounting for potential patent term extensions and adjustments.

Patent Term and Term Extensions

Individual patents have terms for varying periods depending on the date of filing of the patent application or the date of patent issuance and the legal term of patents in the countries in which they are obtained. Generally, utility patents issued for applications filed in the United States are granted a term of 20 years from the earliest effective filing date of a non-provisional patent application. In addition, in certain instances, the term of a U.S. patent can be extended to recapture a portion of the United States Patent and Trademark Office, or the USPTO, delay in issuing the patent as well as a portion of the term effectively lost as a result of the FDA regulatory review period. However, as to the FDA component, the restoration period cannot be longer than five years and the restoration period cannot extend the patent term beyond 14 years from FDA approval. In addition, only one patent applicable to an approved drug is eligible for the extension, and only those claims covering the approved drug, a method for using it, or a method of manufacturing may be extended. The duration of foreign patents varies in accordance with provisions of applicable local law, but typically is also 20 years from the earliest effective filing date. All taxes, annuities or maintenance fees for a patent, as required by the USPTO and various foreign jurisdictions, must be timely paid in order for the patent to remain in force during this period of time.

The actual protection afforded by a patent may vary on a product-by-product basis, from country to country, and can depend upon many factors, including the type of patent, the scope of its coverage, the availability of regulatory-related extensions and the availability of legal remedies in a particular country and the validity and enforceability of the patent.

Our patents and patent applications may be subject to procedural or legal challenges by others. We may be unable to obtain, maintain and protect the intellectual property rights necessary to conduct our business, and we may be subject to claims that we infringe or otherwise violate the intellectual property rights of others, which could materially harm our business. For more information, see the section titled “Risk Factors—Risks Related to Our Intellectual Property.”

Trade Secrets and Know-How

We also rely on trade secrets, know-how, continuing technological innovation and confidential information to develop and maintain our proprietary position and protect aspects of our business that are not amenable to, or that we do not consider appropriate for, patent protection, including our proprietary processes for expanding and activating therapeutic quantities of gamma-delta T cells and modified gamma-delta T cells. We seek to protect our proprietary technology and processes, in part, by confidentiality agreements and invention assignment agreements with our employees, consultants, scientific advisors, contractors and others who may have access to proprietary information, under which they are bound to assign to us inventions made during the term of their employment or term of service. These agreements may be breached, and we may not have adequate remedies for any breach. In addition, our trade secrets may otherwise become known or be independently discovered by competitors. To the extent that our contractors, commercial partners, collaborators, employees, and consultants use intellectual property owned by others in their work for us, disputes may arise as to the rights in related or resulting know-how and inventions. For more information, see the section titled “Risk Factors—Risks Related to Our Intellectual Property.”

We also seek to preserve the integrity and confidentiality of our data and trade secrets by maintaining physical security of our premises and physical and electronic security of our information technology systems.

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 required by the FDA before biologic product candidates may be marketed in the United States generally involves the following:

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completion of preclinical laboratory tests and animal studies performed in accordance with the FDA’s current Good Laboratory Practices regulation;

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submission to the FDA of an IND, which must become effective before clinical trials may begin and must be updated annually or when significant changes are made;

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approval by an independent Institutional Review Board, or IRB, or ethics committee at each treatment site before the trial is commenced;

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performance of adequate and well controlled human clinical trials to establish the safety, purity and potency of the proposed biologic product candidate for its intended purpose;

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preparation of and submission to the FDA of a biologics license application, or BLA, after completion of all pivotal clinical trials;

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

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

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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 cGMP and to assure that the facilities, methods and controls are adequate to preserve the biological product’s continued safety, purity and potency, and of selected clinical investigation sites to assess compliance with Good Clinical Practices, or GCP; and

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

Preclinical and Clinical Development

Prior to beginning the first clinical trial with a product candidate, we must submit an IND to the FDA. An IND is a request for authorization from the FDA to administer an investigational new drug product 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.

Supervision of human gene transfer trials includes evaluation and assessment by an Institutional Biosafety Committee, or IBC, a local institutional committee that reviews and oversees research utilizing recombinant or synthetic nucleic acid molecules at that institution, as set forth in the NIH Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules, or NIH Guidelines. 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.

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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.

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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.

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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. These so- called Phase 4 studies may 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, or for biologics, the safety, purity and potency. 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

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 pertinent 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. The submission of a BLA requires payment of a substantial application user fee to FDA, unless a waiver or exemption applies, and the sponsor of an approved BLA is also subject to an annual program fee.

INAB US Equity

INAB · 10-K · period ended 2023-12-31

Item 1. Business.

INAB US Equity☆

INAB · 10-K · period ended 2023-12-31

Item 1. Business.

INAB US Equity