10-K
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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 10-K
(Mark One)
For the fiscal year ended December 31, 2024
OR
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 filing 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 $0.85 per share of the Registrant’s common stock as reported on the Nasdaq Stock Market LLC on June 28, 2024, the last business day of the Registrant’s most recently completed second quarter was $29.0 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 10, 2025 was 81,258,763.
DOCUMENTS INCORPORATED BY REFERENCE
Portions of the definitive proxy statement for the 2025 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, 2024.
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Table of Contents
Page
PART I
Item 1. Business 1
Item 1A. Risk Factors 45
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 128
Item 9B. Other Information 129
PART III
Item 10. Directors, Executive Officers and Corporate Governance 130
Item 11. Executive Compensation 130
Item 14. Principal Accountant Fees and Services 130
PART IV
Item 15. Exhibits and Financial Statement Schedules 131
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 7, 9, 13, 19, 24, 26 and 27 of this Annual Report were created with biorender.com.
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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 operations, 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, international tariffs, 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.
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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.
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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 and T cell engagers ("TCEs") for cancer and autoimmune diseases. Gamma-delta T cells are a specialized population of T cells that possess unique properties. They are naturally occurring immune cells that can intrinsically regulate immune responses and to 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. Multiple studies have demonstrated the robust tumor-killing ability of gamma-delta T cells and superior outcomes in cancer patients demonstrating elevated levels of gamma-delta T cells. Recently published literature demonstrated that gamma-delta T cells are predictive of better survival outcomes even in melanoma patients being treated with checkpoint inhibitors and in leukemia patients being treated with chimeric antigen receptor T cell (“CAR-T”) therapies. 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 cancers.
We develop ex vivo expanded and activated gamma-delta T cell candidates and TCEs 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 ("iPSC"), genetically modified cell therapy approaches, and TCEs that are designed to effectively identify and eradicate tumor and targeted cells. We believe we are the most clinically advanced gamma-delta T cell-focused company and are utilizing our suite of DeltEx platform technologies to potentially 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 the treatment of cancer and other diseases with unmet needs
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. We believe that our unique corporate insights into the advanced manufacturing and biology of gamma-delta T cells provide us with an innovative platform to treating cancer that capitalizes on the particular properties of gamma-delta T cells. We currently have two novel programs in the clinic that have demonstrated durable complete tumor remissions. We have used our DeltEx platform to create our pipeline of innovative allogeneic, autologous, iPSC and/or genetically modified product candidates designed to effectively target and potentially eradicate disease and improve patient outcomes.
To date, we have conducted two main investigator-sponsored Phase 1 clinical trials to test our gamma-delta T cell technologies in cancer patients. INB-100 tests our DeltEx Allogeneic (“Allo”) gamma-delta T cells in older patients with high-risk leukemias undergoing haploidentical stem cell transplantation (“HSCT”) and INB-200 tested our DeltEx Drug Resistant Immunotherapy (“DRI”) in newly diagnosed glioblastoma (“GBM”) patients. Both trials have demonstrated long-term durable remissions with patients remaining alive and remission for greater than three years.
INB-100, our first allogeneic DeltEx product candidate, was developed to assess the safety and tolerability of donor-derived expanded and activated gamma-delta T cells that do not undergo additional genetic modification. The Phase 1 trial of INB-100 has completed primary enrollment and a recommended Phase 2 dose (“RP2D”) has been determined. We presented updated data at the 2025 Transplantation & Cellular Therapy ("TCT") Meeting in February 2025, demonstrating that 100% of acute myeloid leukemia (“AML”) patients across both original and expansion cohorts remain in complete remission (“CR”), with a median follow-up of 20.1 months. Furthermore, these AML patients demonstrated one-year progression-free survival (“PFS”) and overall survival (“OS”) rates, exceeding real-world control groups obtained from both the Center for International Blood and Marrow Transplant Research (“CIBMTR”) and historical patient outcomes data from the Kansas University Cancer Center (“KUCC”) where the study is currently being conducted. Patients treated with INB-100 are demonstrating prolonged and durable remissions supported by gamma-delta T cell persistence beyond one year. In 2024, we held a meeting with the U.S. Food and Drug Administration (“FDA”) and received regulatory guidance on a Phase 2 trial of INB-100 for the treatment of AML with relapse-free survival as the primary endpoint in a randomized controlled trial. To further de-risk this registrational pathway, we are currently enrolling in an expansion cohort, with a target of up to 25 patients, to confirm the improvements in relapse free and OS observed to date. We expect to complete the enrollment of the expansion cohort in 2025, with long-term follow-up results anticipated in late 2025 and in 2026.
Our DeltEx DRI technology is an innovative and proprietary platform that genetically engineers gamma-delta T cells to allow synergistic combinations with conventional standard-of-care chemotherapies for the treatment of solid-tumor cancers. Our proprietary genetic engineering hijacks the tumor’s own resistance mechanism to a chemotherapy to protect our DRI gamma-delta T cells from the killing effects of such chemotherapies. This allows combination therapies in a manner to drive deeper tumor responses, with the potential for better patient outcomes. Our first indication is newly diagnosed GBM where patient
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dosing in the investigator-sponsored Phase 1 trial of INB-200 (NCT04165941) has been completed and we continue to follow patients for PFS and OS. We presented an oral plenary presentation at the Society of Neuro-Oncology ("SNO") Annual Meeting in November 2024 where we provided longer-term patient follow-up. As of October 18, 2024, four patients remained alive and in remission with the longest remaining in remission for a duration exceeding 40.5 months. To date, patients who received repeated doses of INB-200 demonstrated a 79% increase in median PFS (12.4 months) as compared to the standard-of-care Stupp regimen (6.9 months) and an almost 50% increase in median PFS as compared to the 8.3 months in the three patients treated in Cohort 1 of this trial, each who received only a single dose of INB-200.
INB-400 is the corporate-sponsored investigational new drug application (“IND”) for the Phase 2, multi-center clinical trial for our DeltEx DRI technology for the treatment of newly diagnosed GBM. While the IND remains open and we continue to treat any enrolled patients, in September 2024, we implemented a pipeline prioritization by suspending enrollment in the Phase 2 Trial of INB-400. This trial sought to expand the assessment of genetically modified, DRI gamma-delta T cells in newly diagnosed GBM patients in multiple centers across the United States. We will continue to follow any treated patients for safety, PFS and OS with preliminary data to be reported in 2025. We believe our DeltEx DRI gamma-delta T cell therapeutic approach is demonstrating clinical activity and can be applied to multiple solid tumor types. We are seeking alternative funding sources and strategic opportunities to potentially partner this program. In April 2023, we received Orphan Drug Designation for the autologous and allogeneic INB-400 products from the FDA, covering a broad range of malignant glioma indications, including relapsed and newly diagnosed GBM.
Most recently we introduced INB-600, our proprietary and internally developed TCE platform. This platform represents a potentially revolutionary advancement in immunotherapy, harnessing the power of gamma-delta T cells through a distinctive mechanism that optimizes effector function and targeted cytotoxicity. To date, we have observed novel properties by facilitating the exponential expansion of activated gamma-delta T cells to potentially offer a sustained and potent anti-tumor response. This unique capability may not only enhance the immediate cytotoxic effects but can also build a more durable and long-lasting immune response, essential for combating both solid tumors and resistant leukemias/lymphomas as well as sustained target depletion for potential applications in autoimmune diseases. The dual activation and expansion of Vd1+ and Vd2+ gamma-delta T cell subsets further broadens our therapeutic potential, merging the rapid antigen processing of Vd2+ cells with the enduring stability and potential tissue penetrating properties of Vd1+ cells as an innate immune force multiplier. We believe INB-600 positions us with a promising candidate for a range of potential applications, from solid tumors to autoimmune diseases, with the goal of offering a comprehensive approach to immune system modulation and disease treatment. We have demonstrated that a CD19 targeted gamma-delta TCE can eliminate the targeted cells in a dose-dependent manner. We expect to present additional preliminary preclinical data at a medical meeting in spring 2025.
We also have a portfolio of preclinical programs in development. These include INB-300, which is applicable to both solid and liquid tumors using a targeted non-signaling gamma-delta T cell based chimeric antigen receptor (“nsCAR”) construct, and INB-500, which encompasses our ability to produce gamma-delta T cells from iPSCs. iPSCs represent a significant step toward next generation approaches of cellular manufacturing for true allogeneic and potentially "off-the-shelf" innate cell therapies. We presented additional preclinical data for INB-300, demonstrating our proof-of-concept in vitro studies, run in triplicate, against the leukemia antigen targets CD33 and CD123, at the American Association for Cancer Research ("AACR") Annual Meeting in 2024. These data demonstrated the ability of our nsCAR constructs to distinguish between tumor tissue and healthy tissue. We plan to continue to optimize the nsCAR construct for advancement towards animal models, IND enabling studies and opportunities for potential partnership.
Going Concern
Our financial statements have been prepared in conformity with generally accepted accounting principles which contemplate continuation of the Company on a going concern basis. The going concern basis assumes that assets are realized, and liabilities are extinguished in the ordinary course of business at amounts disclosed in the financial statements. We have not yet generated product sales and, as a result, have experienced operating losses since inception. We expect to incur additional losses in the future as we advance our product candidates through clinical trials, seek to expand our product candidate portfolio through developing additional product candidates, grow our clinical, regulatory and quality capabilities, and incur costs associated with operating as a public company. The actual amount of cash that we will need to operate is subject to many factors. Based on our business strategy, we expect that our existing cash of $11.1 million as of December 31, 2024, along with net proceeds of $3.7 million from the issuance of equity under the ATM program in February 2025 and $0.4 million from the exercise of a portion of our Series C warrants, is not anticipated to fund the Company’s projected operating expenses and capital expenditure requirements for a period of at least 12 months from the date of issuance of these financial statements, and accordingly, there is substantial doubt about the Company’s ability to continue to operate as a going concern. We have taken 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 and the timing of patient enrollment and/or regulatory filings for our preclinical and clinical programs. For more information, see “Going Concern” in
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Part II, “Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations,” below, for a further discussion of our liquidity and the conditions that raise substantial doubt regarding our ability to continue as a going concern.
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. For more information, see “Going Concern” in Part II, “Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations,” below.
Figure 1. Pipeline Chart
Our Strategy
We are dedicated to leveraging our DeltEx platform to develop next generation gamma-delta T 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 clinical product candidate INB-100, while exploring partnership opportunities for our other candidates including INB-400. We are conducting a Phase 1 dose escalation clinical trial of INB-100, our DeltEx Allo product candidate in patients with hematologic malignancies undergoing allogeneic HSCT. We currently expect to complete enrollment of the expansion cohort of the Phase 1 clinical trial in 2025, with updated results throughout 2025 and topline results in 2026. We have completed enrollment in INB-200 our autologous DeltEx DRI program that we initially developed for the treatment of newly diagnosed GBM and are now monitoring patients for long-term follow up. This Phase 1 dose-escalation clinical trial assessing single and multiple dosing schemas was conducted at UAB. We expect to present clinical updates and long-term follow-up in 2025. In September 2024, we paused enrollment in our Phase 2 multi-center clinical trial of INB-400, a company-sponsored clinical program using our autologous DeltEx DRI product candidate to treat newly diagnosed GBM. We will continue to monitor any patients that have been enrolled and have been treated in the INB-400 Phase 2 clinical trial and we expect to provide clinical updates and long-term follow-up throughout 2025, while we continue to explore potential partnership opportunities.
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Advance INB-300, INB-500, and INB-600 into clinical development, subject to additional funding or partnerships and receiving authorization from FDA pursuant to company-sponsored INDs. INB-300 is a DeltEx nsCAR construct, for which we have tested various antigen recognition domains in our efforts to advance a program to IND enabling studies. We presented additional data demonstrating our progress and proof-of-concept for this program at
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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 directed differentiation protocols have demonstrated an ability to generate both Vd1+ and Vd2+ gamma-delta T cell subclones. These cells have high cytotoxicity against cancer cells, and we are exploring avenues for advancement and potential partnering. INB-600 is our proprietary and internally developed TCE platform. Gamma-delta T cells have demonstrated unique benefits against cancer in the clinic and our TCE program has unique features that we believe may be able to overcome some of the challenges with the development of gamma-delta T cell engagers. This program positions us with a promising candidate for a potential range of applications, from solid tumors to autoimmune diseases, offering a comprehensive approach to immune system modulation and disease treatment. We expect to present preliminary preclinical data at a medical meeting in spring 2025.
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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 platform technologies into diseases with significant unmet medical needs.
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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 Cellular Therapy Laboratory at UAB and the Dunbar CAR-T Cell Program at the University of Louisville, we plan to expand our 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 gamma-delta T cell technology pipeline across multiple cancer and autoimmune 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.
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Continue to build value through expansion and continuation of our intellectual property portfolio in relevant geographies. As of December 31, 2024, our intellectual property portfolio consisted of 11 patent families that broadly protect our DeltEx platform and our product candidates, both through composition of matter and method of use. Our patents and pending applications broadly cover the use of allogeneic gamma-delta T cells in HSCT, including in the treatment of AML and other cancers. Our patents also 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. 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.
Gamma-Delta T Cells: Leveraging the Nexus of the Immune System
The Rise of Cell Therapy
There has been significant innovation in the treatment of cancer, including novel cellular therapies, radiotherapies and TCEs. Immuno-oncology utilizes the immune system to identify and kill cancer and/or target cells. Such therapies can either prevent the tumor’s ability to suppress immune attack or to directly utilize immune cells to kill specifically targeted 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.
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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 many tumors means that it is unlikely that any single antigen will be expressed by all tumor cells.
Since 2017, the FDA has approved multiple CAR-T and cellular therapies, which have been transformative in the treatment of certain hematological cancers and now estimated to generate over $4 billion in annual sales in 2024. Of late, as we have moved into more complex and difficult to treat cancers, multiple products in development have succumbed to significant toxicities and/or failed to demonstrate robust and durable tumor remissions. This general lack of efficacy in certain tumors underscores the limited therapeutic window and inherent challenges of CAR-T approaches. Many of the limitations of CAR-T cell therapies are related to the fundamental dynamics of complex, heterogeneous 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 ("TME"), due to physical barriers such as tumor bulk, (iii) the lack of tumor antigens, which are ubiquitously and uniquely expressed on tumor cells resulting in off-tumor toxicities, (iv) potential limited T cell function due to the immunosuppressive TME, including regulatory T cells ("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 ("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, multiple programs have also attempted to leverage natural killer CAR based therapies ("CAR-NK") to amplify the innate immune response to cancer with limited success. 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 ("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 ("CRS"), which can lead to substantial morbidity and mortality with immune
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CAR-T therapies; and (ii) CAR-NKs are not major histocompatibility complex ("MHC"), restricted and can be infused from a donor to a patient without complex and expensive genetic engineering to prevent graft versus host disease ("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 recent years, CAR-NK cell clinical data proved 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 over the past few years.
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 and autoimmune disease .
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 repeatedly demonstrated both an increase in the number gamma-delta T cells and their continued presence in the TME, following infusion(s) 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. Surprising data from our own INB-100 program in leukemia patients undergoing HSCT had demonstrated for the first time the in vivo expansion and long-term persistence of allogeneic gamma-delta T cells for as long as 365 days.
Gamma-delta T cells are multifunctional with a complex receptor repertoire including the semi-invariant T cell receptor ("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 or NK cells through inhibition by matched KIR .
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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 ("NKRs"), such as NKG2D, DNAM-1, and toll-like receptors ("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.
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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 ("DC") maturation by conveying danger associated molecular patterns ("DAMPs"), and pathogen associated molecular patterns ("PAMPs") to such cells. Certain subtypes of gamma-delta T cells also function directly as professional antigen presenting cells ("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 allow these cells to be used "off-the-shelf". Gamma-delta T cells also do not significantly secrete IL-6, a driver of CRS, which has been a fatal complication in CAR-T and CD3 TCEs 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 ("CD95L") and tumor necrosis factor-related apoptosis-inducing ligand ("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 and/or targeted 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 ("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.
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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 ("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.
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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 ("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
More recent studies continue to support these historical observations even when the primary therapy is another modality such as checkpoint inhibitors or CAR-T therapy. In 2024, a paper published in Nature Cancer demonstrated that gamma-delta T cells were associated with better responses in melanoma patients being treated with immune checkpoint inhibitors, especially in those patients that had low neoantigen levels. This is contrary to conventional dogma whereby checkpoint inhibitors are thought to have greater efficacy in those cancers with high neoantigen load and mutational burden. The authors postulate that gamma-delta T cells are probably an important constituent of tumor-infiltrating lymphocyte populations, allowing surveillance of tumors and are associated with a better prognosis. In a separate study published in Cell Reports Medicine, the authors utilized single-cell analysis to examine cellular dynamics in patients treated with CD19 CAR-T cells. It was validated that CAR+ gamma-delta T cell expansion is correlated with treatment efficacy in both B-ALL and DLBCL. The authors noted that two patients who experienced a “massive” in vivo expansion of CAR+ gamma-delta T cells had a more sustained clinical response and that these trends were also observed for CAR- gamma-delta T cells
While gamma-delta T cells have demonstrated clinical association with specific tumor responses, there have been significant hurdles to developing them as cell therapies and TCEs, 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 or target in vivo, or in the body, in quantities sufficient to meet the significant levels generally required for efficacious 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.
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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 gamma-delta T cell therapies 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, scalable manufacturing and targeting 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, genetically modified product candidates, and/or TCEs that are designed to effectively target and potentially eradicate disease to 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 and we believe it uniquely enables us to potentially develop therapeutic cellular therapy candidates 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 ("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 systems 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. Our manufacturing allows us to scale, while maintaining quality controls, which would be challenging with manual lab-scale processes. We have optimized transduction and cell expansion in processes 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 by the FDA. 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.
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Unique T cell engager properties. We have developed a unique gamma-delta T cell based TCE that possesses properties that have not previously been demonstrated by others to our knowledge. We believe our TCEs have the ability to eliminate specifically targeted cells but can overcome the challenges of low gamma-delta T cell numbers through the significant expansion of gamma-delta T cells in vivo. Our TCE is a pan-gamma-delta TCE that engages both the Vd1+ and Vd2+ TCR populations. The unique properties of these cells may allow for deeper responses, and potentially better safety as gamma-delta T cells secrete lower amounts of IL-6 and may reduce the incidence of CRS
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as is common with both alpha-beta CAR-T and CD3-based TCEs. Ultimately, TCEs have a simpler manufacturing process, with lower costs, allow for repeat dosing and avoid lymphodepleting chemotherapies, which would be important in autoimmune indications.
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 Vd2+, and the Vd1+. 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. Our early clinical programs focused on developing therapeutic candidates using Vd2+ cells, due to certain advantages over the Vd1+ subset in certain indications, but there is a utility for the Vd1+ subset as well. Vd1+ cells have previously shown lower predisposition towards exhaustion and 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 and through TCEs. For the first time that we are aware of, our INB-600 TCE program has the potential to target both the Vd1+ and Vd2+ subpopulations simultaneously. 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-100 for the Treatment of Patients with Hematological Malignancies Undergoing HSCT
INB-100 is an allogeneic DeltEx product candidate created from healthy donors, consisting of allogeneic, expanded activated gamma-delta T cells, with the goal of testing the safety of allogeneic gamma-delta T cells, reducing relapse, and improving overall survival in patients with hematological malignancies who have undergone allogeneic HSCT.
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 ("CML") in blast phase and myelodysplastic syndromes ("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 "reset" and repopulate their hematopoietic system. Unfortunately, residual leukemic cells often exist, resulting in a leukemic relapse rate of approximately 25% within the first 100 days and up to 50% at one year.
Our Solution — INB-100 for the Treatment of Patients with Hematological Malignancies Undergoing HSCT
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.
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INB-100 is an allogeneic DeltEx product candidate created from healthy donors, consisting of allogeneic, expanded activated gamma-delta T cells, with the goal of testing the safety of allogeneic gamma-delta T cells to boost gamma-delta T cell levels and improve 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 as we are now achieving blood levels of gamma-delta T cells that have previously been demonstrated to be associated with higher rates of overall survival.
Phase 1 Clinical Trial of INB-100
We are collaborating with Joseph McGuirk, D.O. and the team at the University of Kansas Cancer Center, to conduct an investigator-sponsored Phase 1 dose escalation clinical trial of INB-100 to assess the safety and tolerability 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 add an expansion cohort of up to an additional 15 patients, for a total of up to 25 treated patients.
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 8. INB-100 Administration
As depicted in Figure 8 above, patients are initially treated using a standard HSCT protocol, originally developed at Johns Hopkins University (the "Hopkins protocol"), under which these patients undergo non-myeloablative or reduced intensity conditioning ("RIC") 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 manufactured 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 25% within the first 100 days and up to 50% at one year and even greater in those patients with high-risk and/or complex cytogenetics. More recent data presented at the American Society of Hematology (“ASH") 2023 annual meeting, in a 2,200 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
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days of neutrophil engraftment, our INB-100 product candidate is 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.
The swimmers plot in Figure 9 below depicts the patient outcomes in the INB-100 Phase 1 trial. We believe the relapse free survival data as of January 17, 2025 (the "Cutoff Date"), which was presented at the 2025 TCT Meeting in February 2025, combined with the tolerability profile of INB-100, are encouraging for the treatment of older, high-risk leukemia patients with complex disease. Enrollment in the expansion cohort is ongoing to confirm the improvements in relapse free and overall survival observed to date. To further de-risk a future registrational randomized control trial, we are also seeking to add a parallel observational cohort to the Phase 1 trial to prospectively assess leukemia patients and enable comparison between patients receiving INB-100 to those who only receive standard haplotransplantation with RIC. As of the Cutoff Date, 100% of patients with AML remain relapse-free after receiving their dose of INB-100 after a median follow-up of 20.1 months. A total of 17 patients with leukemic diagnoses were enrolled as of the Cutoff Date and as previously reported, three patients had relapsed and, of those, two had died due to disease progression. The patients who relapsed to date, included other leukemic diagnoses (ALL, MDS, and MDS/MPN overlap with concurrent TP53 mutations). Across the initial 10 patient cohort, median morphologic CR was 18.8 months across all patients and 23.3 months for AML patients as of the Cutoff Date. Further, gamma-delta T cells demonstrated in vivo expansion and long-term persistence through 365 days, a first for any donor-derived, allogeneic cellular therapy product. Along with our investigators, we believe patient outcomes in the trial to date are surpassing that of similar leukemia patients, including those with AML undergoing haploidentical transplantation without receiving INB-100. We expect to complete the enrollment of the expansion cohort in 2025, with long-term follow-up results anticipated in late 2025 and in 2026.
Figure 9. Summary of Patients Treated in INB-100 Phase 1 Trial
As shown in Figure 10 below, this compares favorably with real world data from AML patients retrieved from the Center for International Blood & Marrow Transplant Research (“CIBMTR”) national database demonstrating a 32.2% relapse rate (n=679) and 25.3% mortality rate (n=684) at one-year and comparative data from the University of Kansas Cancer Center demonstrating a one-year 42.6% relapse rate (n=31) and 33.3% mortality (n=36, 2016-2024). We believe the high relapse and mortality rates at University of Kansas Cancer Center compared to the CIBMTR data as it is a center of excellence for transplantation and is a major tertiary referral center for the Midwest region. Patients referred to and treated at the center are likely sicker and have more complex disease.
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Figure 10. Summary of Patients Treated in INB-100 vs. Real World Data
As of January 17, 2025, there were eight AML patients in this INB-100 trial who have remained in CR for periods greater than one year, four for greater than two years and one nearing their five-year anniversary in remission. Notably, at the 2024 ASH Annual Meeting held in December 2024, data was presented that 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 one-year post-transplant as shown in Figure 11 below.
Figure 11. Summary of Patients Treated in INB-100 gamma-delta T cell persistence and expansion
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 immune effector cell-associated neurotoxicity syndrome (“ICANS”). Approximately 56% of patients across all time points have sustained steroid responsive Grade 1/2 GvHD that has been mostly resolved with steroids therapy. No events of Grade 3 or greater GvHD, CRS or ICANS has been observed. Three patients have reported mild chronic GvHD.
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In 2024 we held a Type B meeting with the FDA and received regulatory guidance to advance INB-100 as a post-transplant maintenance therapy for AML, with relapse-free survival designated as the primary endpoint. AML represents one of the most common leukemias, with approximately 21,000 newly diagnosed patients annually, which is also widely treated with allogeneic HSCT. To validate the observed improvements in relapse-free and overall survival and further de-risk a future registrational randomized controlled trial, we are seeking to add a parallel observational cohort as a control. This parallel cohort will try to prospectively assess leukemia patients undergoing haploidentical transplantation without receiving INB-100, enabling comparison with patients treated with INB-100. Along with our investigators, we believe patient outcomes in the trial to date are surpassing that of similar leukemia patients, including those with AML undergoing haploidentical transplantation without receiving INB-100. The expansion cohort is currently enrolling and we expect to complete this additional expansion cohort in 2025, with long-term follow-up results anticipated in late 2025 and in 2026.
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.
INB-200 and 400 for the Treatment of Solid Tumors
INB-200 is a genetically modified, autologous gamma-delta T cell product to be administered in combination with the current standard-of-care chemotherapy in newly diagnosed GBM, where median PFS has remained at 6 to 7 months since 2005. We engineered INB-200 to be resistant from being killed by 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 ("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 initially developed INB-200 to treat newly diagnosed patients with GBM during the maintenance phase following resection and initial radiation and chemotherapy. The fully enrolled INB-200 investigator-sponsored Phase 1 clinical trial is a dose escalation protocol for newly diagnosed GBM patients conducted at the Heersink School of Medicine and O’Neal Comprehensive Cancer Center at the University of Alabama at Birmingham ("UAB"). The protocol is designed to evaluate single and multi-dose schedules of a fixed number cell dose of the DeltEx DRI gamma-delta T cell therapy. We have completed enrollment and expect to provide clinical updates and long-term follow-up throughout 2025.
In September 2024, while the IND remains open and we continue to treat enrolled patients, we suspended enrollment of additional patients in our Phase 2 multi-center clinical trial of INB-400, for the treatment of newly diagnosed GBM. This trial sought to expand the assessment of genetically modified, DRI gamma-delta T cells in newly diagnosed GBM patients in specialized centers across the United States. We will continue to follow any enrolled patients for safety, PFS and OS with
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preliminary data to be reported in 2025. We have completed patient dosing in the investigator-sponsored Phase 1 trial of INB-200 (NCT04165941) in newly diagnosed GBM patients. We presented an oral plenary presentation at the SNO Annual Meeting in November 2024 where we provided longer-term follow-up and additional data supporting the activity of our DRI gamma-delta T cell approach from the Phase 1 trial of INB-200. As of October 18, 2024, the clinical data demonstrates that 50% of patients who received repeated doses (n=10) remained alive and in remission beyond the expected median OS from standard-of-care ("Stupp regimen") with temozolomide (“TMZ”), while none of the patients who received a single dose (n=3) achieved this outcome. As of that date, 92% of evaluable patients treated in the investigator-sponsored trial exceeded the median PFS of 6.9 typically months achieved by the Stupp regimen, with a majority exceeding their expected PFS based on their age and the MGMT status of their tumors. Patients who received repeated doses of INB-200 demonstrated a 79% increase in median PFS (12.4 months) as compared to the Stupp regimen and an almost 50% increase in median PFS as compared to the 8.3 months in the three patients treated who received only a single dose of INB-200 in Cohort 1. One patient with an IDH-mutant glioma remains alive and progression free at over 40.5 months. In recently updated clinical trial results of another experimental therapy, IDH-mutant patients demonstrated a median PFS of 11.4 months in the control arm with all patients having relapsed by 31 months in the control arm (n=163 patients). We believe our DRI gamma-delta T cell therapeutic approach can be applied to multiple solid tumor types and plan to seek strategic alternatives and to potentially partner this program. In April 2023, we received Orphan Drug Designation for the autologous and allogeneic INB-400 products from the FDA, covering a broad range of malignant glioma indications, including relapsed and newly diagnosed GBM.
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 3.5 in 100,000 individuals, with almost 14,500 new cases having been estimated in 2023 by the National Brain Tumor Society ("NDTS"). 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 six or seven months 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
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 the selection of residual tumor cells that are chemotherapy resistant and lead to disease recurrence. 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 engineered INB-200 and INB-400 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 developed in response to it. By combining our DeltEx DRI therapeutic candidate concurrently with alkylating chemotherapies,
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our approach can promote the upregulation of stress ligands across all three of these categories, making the GBM cells identifiable by our gamma-delta T 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 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 by intravenously delivered CAR-T 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 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 ("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 conducted an investigator-sponsored Phase 1 repeat dose escalation trial of INB-200 at UAB. We have completed enrollment and patient dosing of the Phase 1 trial with 13 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. We believe that the survival data along with histopathology and radiographic data are indicative of positive treatment effects, which highlight the potential of our genetically modified, chemotherapy-resistant gamma-delta T cells as a potential first-in-class therapy for patients with solid tumor cancers such as GBM.
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.
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INB-400 (Autologous and Allogeneic): Phase 2 Clinical Trials
Enrollment in the INB-400 Phase 2 trial was suspended in September 2024 as part of our cash conservation efforts. We are working to identify potential alternative sources of funding and with advisors to seek potential partnership opportunities for this asset. INB-400 was 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. The trial was also designed to assess the activity of allogeneic cells in the relapsed setting in a potentially registrational arm. The IND remains open as a number of patients have been enrolled from multiple centers and patients continue to undergo treatment. We will follow these patients for safety, progression-free and overall survival with preliminary data expected to be reported in 2025.
Figure 12. INB-200 and INB-400 Administration Protocol
The decision to combine DeltEx DRI gamma-delta T cells 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 sought to attack any residual tumor cells when they are most vulnerable with immune cells that are as healthy as possible. By combining DeltEx DRI gamma-delta T cells with maintenance TMZ, we sought 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 via intracranial catheter injection, as shown in Figure 12 above, within four hours of receiving intravenous dosing with TMZ on day one of the maintenance cycle. Standard-of-care oral dosing of TMZ continues for the four subsequent days during each 28-day treatment cycle, as shown in Figure 13 below. Depending on which dose cohort they are enrolled in, patients were administered either one, three or six injections of INB-200.
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Figure 13. Treatment and Manufacturing Timeline of the INB-200 Phase 1 Trial
In 2024, we provided multiple clinical updates for INB-200 including a plenary oral presentation at the 2024 SNO Annual Meeting in November 2024 and, a poster presentation at the 2024 ASCO Annual Meeting. At SNO, we indicated that as of October 18, 2024, 23 patients with newly diagnosed GBM have been enrolled in this trial and a total of 13 patients have been treated with INB-200, including three patients in Cohort 1, four patients in Cohort 2 and six patients in Cohort 3. All Cohorts had completed dosing as of December 31, 2024 and continue to be monitored. The trial assessed the administration of 1x107 cells per dose across three different dosing regimens increasing from a single dose in Cohort 1, three doses in Cohort 2, and six doses in Cohort 3. No infusion reactions, CRS, neurotoxicity, or other dose limiting toxicities ("DLTs"), or treatment-related series adverse events ("SAEs"), or treatment-emergent adverse events ("AEs"), were observed in Cohorts 1 2, or 3 to date. 50% of patients who received repeated doses (n=10) remained alive and in remission beyond the expected median OS from standard-of-care Stupp regimen while none of the patients who received a single dose (n=3) achieved this outcome. As of that date, 92% of evaluable patients treated with INB-200 for GBM surpassed a median standard-of-care Stupp regimen PFS of 6.9 months, with a majority exceeding their expected PFS based on their age and the MGMT status of their tumors and five patients remain alive with one IDH-mutation patient, with a grade 4 brain tumor, remaining progression free at 40.5 months post treatment. In 2023, Novocure announced the final results of the Phase 2 TOP study of TTFields (Optune) plus Merck’s pembrolizumab plus maintenance TMZ in patients with newly diagnosed GBM. In 26 GBM patients with a median age of 60.5 years, 73% with MGMT-unmethylated GBM, and 11.5% with an IDH-mutation, median PFS was reported as 12 months, surpassing the 5.8 months of a case-matched control cohort.
Following treatment, all patients are 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, decreased appetite, hydrocephalus, attributable to TMZ, radiotherapy or disease. One subject had Grade 3 treatment of unrelated AEs of urinary tract infection, dehydration, and thrombocytopenia. There were no treatment related deaths, any reports "ICANs, or CRS and repeat dosing has not changed the toxicity profile of this agent as of October 18, 2024.
Figure 14. Summary of Patients Enrolled in INB-200 Phase 1 Trial
Figure 14 above depicts treatment outcomes for patients treated as of October 18, 2024. These data demonstrate that patients have exceeded expected PFS based on their age and tumor MGMT status and have exceeded the median PFS predicted of this patient population (6-7 months). Of the three patients who received a single dose of INB-200 median PFS was 8.3 months and across all patients (n=10) who received multiple doses, median PFS increased by almost 50% to 12.4 months, surpassing the median PFS results reported by Novocure above. Biopsy results are confirming the infiltration and persistence of gamma-delta T cells along with CD3+ and CD8+ T cells within the brain tumor microenvironment in patients following treatment with INB-200. In one patient (022), we demonstrate histopathology from paired biopsies at first diagnoses and upon relapse after a receiving six doses of DeltEx DRI gamma-delta T cells (brown stain) in Figure 15 below.
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Figure 15. Gamma-Delta T cells, CD3+ and CD8+ T Cells Infiltrating and Persisting in Brain Tissue
We have completed enrollment and we expect to provide clinical updates and long-term follow-up at medical meetings throughout 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
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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 16 below.
Figure 16. Increased NKG2D Ligand Expression Observed on TMZ-Resistant Tumor Cells Treated with TMZ
As shown in Figure 17 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.
Figure 17. Cancer Stem-Like Cells Co-Express Stem-Cell Markers and NKG2D Ligands
Treatment with TMZ demonstrated that NKG2D ligand expression can also be upregulated several fold on GBM stem-like cells, as depicted in Figure 18 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.
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Figure 18. 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 19 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.
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Figure 19. 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. 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. We observed that this gene modification did not alter other properties of these gamma-delta T cells, including their cytotoxicity against target cells.
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.
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Figure 20. Improved Survival Observed in Both TMZ-Sensitive and TMZ-Resistant GBM 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 21 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 21. Histopathology Demonstrates No Residual GBM in Mice
Our Additional Product Candidates
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 and are designed to eliminate tissues expressing the target irrespective of whether they
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are tumor or healthy tissues. Data from these CD19 CAR-Ts demonstrated 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 of preserving healthy tissue 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 and potentially less toxic approach. These constructs utilize 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 (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 the AACR Annual Meeting in 2024, we presented data of an nsCAR targeting CD33 and co-expressing IL-15 for AML. Initial cytotoxicity data demonstrated ns33CAR+IL-15 killing of approximately 9.5% against normal CD34+ hematopoietic progenitor cells ("HPCs") versus an average of approximately 63.2% killing against the MOLM-13 AML cell line, a 6.7x difference at an E:T ratio of 8:1. 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.
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 22 below, published in the Nature.com article “T cells without limitation” in March 2023.
Figure 22. INB-300, a DeltEx Non-Signaling CAR Constructs
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
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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 as shown in Figure 23 below.
Figure 23. INB-300 – ns-dCAR-mb15 Enhanced Cytotoxicity against AML
To date, we have created nsCAR constructs against antigens, including the peptide chlorotoxin ("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 (E:T ratio=2:1, 79.7% versus 5.2%) when both express the CD19 target antigen as shown below in Figure 24.
Figure 24. INB-300 – ns19CAR γδ T vs. Leukemias: Normalized Results
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At our R&D Day and at the 2024 AACR conference in April 2024, we presented the initial data of an nsCAR targeting CD33 and co-expressing IL-15 for AML, as shown in Figure 25 below. Initial cytotoxicity data demonstrated ns33CAR+IL-15 killing of approximately 3% against CD34+ HPCs versus an average of approximately 65% killing against three separate AML cell lines at an E:T ratio of 8:1.
Figure 25. INB-300 – ns33CAR-CAR-γδ T vs. AML and Healthy donor CD34+ HSPCs
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.
INB-600: Gamma-Delta T Cell Engager
Our proprietary and internally developed gamma-delta TCE recognizes pan gamma-delta T cell and is not limited to a single gamma-delta T cell subset. INB-600 has the potential to expand and activate gamma-delta T cells broadly, including both the Vd1+ and Vd2+ subsets. This combines the advantages of Vd2-mediated antigen presentation and immunosurveillance, along with the long-term durability and potential tissue resident characteristics of Vd1+ T cells. This potentially maximizes both immediate and sustained immune responses, leveraging the natural cytotoxic properties of gamma-delta T cells as represented in Figure 26 below. In March 2025 we announced a preliminary preclinical program in INB-619, a gamma-delta TCE targeting CD19 for both oncology and autoimmune diseases. We have demonstrated that a CD19 targeted gamma-delta TCE can eradicate
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B cells in preclinical models, maintaining depletion as gamma-delta T cells expand in response to TCE stimulation. This program potentially fulfills a significant unmet need for a therapy that provides deep B cell depletion, ease of delivery with no required lymphodepletion and one with improved safety and tolerability. We expect to present additional preliminary preclinical data at a medical meeting in spring 2025.
Figure 26. INB-600 – Gamma-delta T Cell Engager
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 ("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.
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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 laboratory facilities 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
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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., 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., Regeneron Pharmaceuticals, 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 payors.
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
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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 cellular 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, 2024, we owned, co-owned or exclusively licensed four issued U.S. patents, seven issued European patents, sixteen other issued foreign patents, 10 pending U.S. applications, two pending PCT applications and 37 other foreign national-stage applications, including five 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-100
Pursuant to the UABRF license agreement, we have licensed one U.S patent application, one issued European patent (which has been widely validated in Europe), one issued Japanese patent, one issued Singaporean patent, one issued Australian patent, one issued Israeli patent and seven foreign national-stage applications. These patents and applications contain claims or supporting disclosures directed to methods of HSCT and 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 PCT application that contains claims or supporting disclosures directed to additional methods of HSCT and treating diseases of interest using INB-100. Patents issuing from this patent application, if any, are expected to expire in 2044, without accounting for potential patent term extensions and adjustments.
INB-200 and INB-400
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 two U.S pending patent applications. These patents and applications contain claims or supporting disclosures directed to the INB-200 and INB-400 composition of matter and to methods of treating diseases of interest using INB-200 and INB-400. 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/INB-400 and Immune Checkpoint Inhibitor Combination Therapy
We co-own one pending U.S. patent application, one issued European patent, one issued Japanese patent, one issued Korean patent, one issued Australian patent, one issued New Zealand patent, and four other national stage patent applications 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 and INB-400 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-200/400 and PARP Inhibitor Combination Therapy
We co-own one pending U.S. patent application and eight 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 and INB-400 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-300
Pursuant to the UABRF license agreement, we have also licensed one issued U.S. patent, one issued Israeli patent, one issued Chinese patent, one issued Korean patent, one pending U.S. patent application and eight 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
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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 and four 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 these patent applications, if any, are expected to expire in 2042, without accounting for potential patent term extensions and adjustments.
In addition, we own one pending PCT application that contains claims or supporting disclosures directed to further INB-300 compositions and to methods of treating diseases of interest. Patents issuing from this patent application, if any, are expected to expire in 2044, without accounting for potential patent term extensions and adjustments.
INB-500
We own one pending U.S. application, a pending European regional phase application and a pending Canadian 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 these patent applications, if any, are expected to expire in 2043, without accounting for potential patent term extensions and adjustments.
INB-600
We own provisional filings on the proprietary T Cell Engager technology, structure, mechanism, potential applications and uses.
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 (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.”
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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 ("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 ("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 ("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 ("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.
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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.
Once a BLA has been submitted, the FDA’s goal is to review standard applications within 10 months after it accepts the application for filing, or, if the application qualifies for priority review, six months after the FDA accepts the application for filing. In both standard and priority reviews, the review process is often significantly extended by FDA requests for additional information or clarification. The FDA reviews a BLA to determine, among other things, whether a product is safe, pure and potent and the facility in which it is manufactured, processed, packed, or held meets standards designed to assure the product’s continued safety, purity and potency. The FDA may convene an advisory committee to provide clinical insight on application review questions. Before approving a BLA, the FDA will typically inspect the facility or facilities where the product is manufactured, including, as applicable, for compliance with Good Tissue Practices. The FDA will not approve an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Additionally, before approving a BLA, the FDA will typically inspect one or more treatment sites to assure compliance with GCP. If the FDA determines that the application,
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manufacturing process or manufacturing facilities are not acceptable, it will outline the deficiencies in the submission and often will request additional testing or information. Notwithstanding the submission of any requested additional information, the FDA ultimately may decide that the application does not satisfy the regulatory criteria for approval.
After the FDA evaluates a BLA and conducts inspections of manufacturing facilities where the investigational product and/or its drug substance will be produced, the FDA may issue an approval letter or a Complete Response letter. An approval letter authorizes commercial marketing of the product with specific prescribing information for specific indications. A Complete Response letter will describe all of the deficiencies that the FDA has identified in the BLA, except that where the FDA determines that the data supporting the application are inadequate to support approval, the FDA may issue the Complete Response letter without first conducting required inspections, testing submitted product lots, and/or reviewing proposed labeling. In issuing the Complete Response letter, the FDA may recommend actions that the applicant might take to place the BLA in condition for approval, including requests for additional information or clarification. The FDA may delay or refuse approval of a BLA if applicable regulatory criteria are not satisfied, require additional testing or information and/or require post-marketing testing and surveillance to monitor safety or efficacy of a product.