TC BioPharm Announces Complete Response in Minimal Residual Disease (MRD) Patient

• First patient in Cohort B achieved CR after 2^nd dose of TCB008

EDINBURGH, Scotland, June 11, 2025 /PRNewswire/ -- TC BioPharm (Holdings) PLC (NASDAQ: TCBP), a clinical-stage biotechnology company pioneering gamma delta T cell therapies for the treatment of cancer, today announced the first patient treated in Cohort B, presenting with detectable Minimal Residual Disease (MRD), is now in complete molecular remission following treatment with the lead drug candidate TCB008.

The response was achieved after the patient's second dose of 250,000,000 gamma delta t-cells, two weeks after treatment began, in total the patient received approximately 500,000,000 gamma delta t-cells over two weeks. The patient received 2 of a possible 4 infusions of TCB008 and continues to be monitored under the care of Dr. Hugues de Lavallade at Guy's and St. Thomas' NHS Foundation Trust and remains in remission state two months after treatment.

This data readout represents a major milestone in TC BioPharm's mission to develop innovative cell therapies that target and eradicate malignant cells with precision and durability. Over 1 million patients are diagnosed with blood cancers globally each year. Patients who initially achieve remission can retain a molecular burden of disease that results in relapse. Multiple factors, including previous treatments, limit treatment options for relapsed patients.

'This patient experienced molecular relapse while continuing low-intensity chemotherapy," said Dr. Hugues de Lavallade, consultant hematologist at Guy's and St. Thomas' NHS Foundation Trust.  "NPM1 transcript levels detected the rising MRD on repeated samples, and chemotherapy was stopped. After two doses of the IMP, given post-lymphodepletion, the patient has now achieved a complete molecular response with no detectable NPM1 transcripts."

"This is an encouraging patient response, and our team is invigorated by this important step forward. We believe TCB008 has the potential to become a foundational component of post-remission therapy for patients with blood cancers, helping to extend survival and improve long-term outcomes, as well as newly diagnosed patients where TCB008 can potentially be impactful as a monotherapy to avoid an arduous bone marrow transplant process" said Bryan Kobel, CEO of TC BioPharm. "Treating MRD effectively halts disease progression before it has the chance to return, and TCB008's targeted immune activity continues to show great promise in this setting. This response to TCB008 heightens our focus on this patient population, where we believe the ability of the gamma deltas to rapidly overwhelm the cancer cells and bring about a high-grade patient response is value-enhancing and commercially impactful."

About TC BioPharm (Holdings) PLC
TC BioPharm is a clinical-stage biopharmaceutical company focused on discovering, developing, and commercializing gamma-delta T-cell therapies for cancer treatment with human efficacy data in acute myeloid leukemia. Gamma-delta T cells are naturally occurring immune cells that embody properties of both the innate and adaptive immune systems and can intrinsically differentiate between healthy and diseased tissue.

TC BioPharm is the leader in developing gamma-delta T cell therapies and the first company to conduct phase II/pivotal clinical studies in oncology. The Company is conducting two investigator-initiated clinical trials for its unmodified gamma-delta T cell product line - Phase 2b/3 pivotal trial in the treatment of acute myeloid leukemia using the Company's proprietary allogeneic CryoTC technology to provide frozen product to clinics worldwide.

Forward Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this Current Report on Form 8-K that do not relate to matters of historical fact should be considered forward-looking statements, including, without limitation, statements regarding the Company's intent or ability to affect any budget savings or execute on any M&A or capital raising strategy.

These statements are based on management's current assumptions and are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause the Company's actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. For other important factors that could cause actual results to differ materially from the forward-looking statements in this Current Report on Form 8-K, please see the risks and uncertainties identified under the heading "Risk Factors" in our Annual Report on Form 10-K for the year ended December 31, 2023, and our other reports filed with the SEC, all of which is available on the Company's Investor Relations website at www.tcbiopharm.com and on the SEC website at www.sec.gov. All forward-looking statements reflect the Company's beliefs and assumptions only as of the date of this Current Report on Form 8-K. The Company undertakes no obligation to update forward-looking statements to reflect future events or circumstances.

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SOURCE TC BioPharm