Biodexa Pharmaceuticals Enrolls First European Patients in Phase 3 Serenta Trial for Familial Adenomatous Polyposis

December 1, 2025

Biodexa Announces Enrolment of First European Patients
into Pivotal Phase 3 Serenta Trial in FAP

Biodexa Pharmaceuticals PLC (“Biodexa” or “the Company”), (Nasdaq: BDRX), a clinical stage biopharmaceutical company developing a pipeline of innovative products for the treatment of diseases with unmet medical needs, is pleased to announce the enrolment of the first three patients by the University of Bonn, Germany into its pivotal Phase 3 Serenta trial of eRapa in patients with familial adenomatous polyposis (FAP), a mostly inherited disease that, if left untreated, almost always leads to colorectal cancer.

Commenting, Dr Robert Hüneburg, gastroenterologist and lead investigator at the University Hospital, Bonn (Germany) said “We are pleased to be the first European center to be activated and to have enrolled the first three patients into the European arm of the Serenta trial.  eRapa has the potential to become an important treatment option for patients with FAP, for whom currently little exists beyond surgical resection of parts or even the entire gastrointestinal tract — often with devastating consequences for quality of life.”

eRapa Phase 3 program

The Serenta trial (NCT06950385) is a double-blind placebo-controlled trial in 168 patients, randomized 2:1 drug / placebo to evaluate the safety and efficacy of eRapa in individuals diagnosed with FAP. All study sites have been identified and are in the process of onboarding. Nine additional European sites will activate during the next 2-3 months across the Netherlands, Spain, Denmark, and Italy. The Serenta trial began enrolling in the US in August 2025. The Serenta trial is supported by a $20 million grant from the Cancer Prevention and Research Institute of Texas. For more information about the Serenta trial, including eligibility criteria and site locations, please visit https://serentatrial.com/ .

About FAP
Familial adenomatous polyposis is a rare, inherited disorder characterized by the development of hundreds to thousands of colorectal polyps and a near-100% lifetime risk of colorectal cancer if left untreated. There is a significant unmet need for effective, less invasive therapies for FAP patients. FAP is characterized as a proliferation of polyps in the colon and/or rectum, usually occurring in mid-teens. There is no approved therapeutic option for treating FAP patients, for whom active surveillance and surgical resection of the colon and/or rectum remain the standard of care. There is a significant hereditary component to FAP with a reported prevalence of one in 5,000 to 10,000 in the US ¹ and one in 11,300 to 37,600 in Europe ² .

About eRapa

eRapa is a proprietary oral capsule formulation of rapamycin, also known as sirolimus. Rapamycin is an mTOR (mammalian Target Of Rapamycin) inhibitor. mTOR has been shown to have a significant role in the signalling pathway that regulates cellular metabolism, growth and proliferation and is activated during tumorgenesis ³ . Importantly, mTOR has been shown to be over-expressed in FAP polyps – thereby underscoring the rationale for using a potent and safe mTOR inhibitor like eRapa to treat FAP. Rapamycin is approved in the US for organ rejection in renal transplantation as Rapamune®(Pfizer). Through the use of nanotechnology and pH sensitive polymers, eRapa is designed to address the poor bioavailability, variable pharmacokinetics and toxicity generally associated with the currently available forms of rapamycin. eRapa is protected by a number of issued patents which extend through 2035, with other pending applications potentially providing further protection beyond 2035.

The Cancer Prevention and Research Institute of Texas
To date, CPRIT has awarded $2.9 billion in grants to Texas research institutions and organizations through its academic research, prevention and product development research programs. CPRIT has recruited 237 distinguished researchers, supported the establishment, expansion or relocation of 43 companies to Texas and generated over $5.7 billion in additional public and private investment. CPRIT funding has advanced scientific and clinical knowledge and provided 7.4 million life-saving cancer prevention and early detection services reaching Texans from all 254 counties. On November 5, 2019, Texas voters overwhelmingly approved a constitutional amendment to provide an additional $3 billion to CPRIT for a total $6 billion investment in cancer research and prevention. Learn more at https://cprit.texas.gov/ .

1.        www.rarediseases.org
2. www.orpha.net

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About Biodexa Pharmaceuticals PLC
Biodexa Pharmaceuticals PLC (listed on NASDAQ: BDRX) is a clinical stage biopharmaceutical company developing a pipeline of innovative products for the treatment of diseases with unmet medical needs. The Company’s lead development programs include eRapa, under development for Familial Adenomatous Polyposis and Non-Muscle Invasive Bladder Cancer; tolimidone, under development for the treatment of type 1 diabetes; and MTX110, which is being studied in aggressive rare/orphan brain cancer indications.

eRapa is a proprietary oral capsule formulation of rapamycin, also known as sirolimus. Rapamycin is an mTOR ( m ammalian T arget O f R apamycin) inhibitor. mTOR has been shown to have a significant role in the signalling pathway that regulates cellular metabolism, growth and proliferation and is activated during tumorigenesis.
Tolimidone is an orally delivered, potent and selective inhibitor of Lyn kinase. Lyn is a member of the Src family of protein tyrosine kinases, which is mainly expressed in hematopoietic cells, in neural tissues, liver, and adipose tissue. Tolimidone demonstrates glycaemic control via insulin sensitization in animal models of diabetes and has the potential to become a first in class blood glucose modulating agent.

MTX110 is a solubilized formulation of the histone deacetylase (HDAC) inhibitor, panobinostat. This proprietary formulation enables delivery of the product via convection-enhanced delivery (CED) at chemotherapeutic doses directly to the site of the tumor, by-passing the blood-brain barrier and potentially avoiding systemic toxicity.

Biodexa is supported by three proprietary drug delivery technologies focused on improving the bio-delivery and bio-distribution of medicines. Biodexa’s headquarters and R&D facility is in Cardiff, UK. For more information visit www.biodexapharma.com .

Forward-Looking Statements
Certain statements in this announcement may constitute “forward-looking statements” within the meaning of legislation in the United Kingdom and/or United States. Such statements are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 and are based on management’s belief or interpretation. All statements contained in this announcement that do not relate to matters of historical fact should be considered forward-looking statements. In certain cases, forward-looking statements can be identified by the use of words such as “plans”, “expects” or “does not anticipate”, or “believes”, or variations of such words and phrases or statements that certain actions, events or results “may”, “could”, “would”, “might” or “will be taken”, “occur” or “be achieved.” Forward-looking statements and information are subject to various known and unknown risks and uncertainties, many of which are beyond the ability of the Company to control or predict, that may cause their actual results, performance or achievements to be materially different from those expressed or implied thereby, and are developed based on assumptions about such risks, uncertainties and other factors set out herein.

Reference should be made to those documents that Biodexa shall file from time to time or announcements that may be made by Biodexa in accordance with the rules and regulations promulgated by the SEC, which contain and identify other important factors that could cause actual results to differ materially from those contained in any projections or forward-looking statements. These forward-looking statements speak only as of the date of this announcement. All subsequent written and oral forward-looking statements by or concerning Biodexa are expressly qualified in their entirety by the cautionary statements above. Except as may be required under relevant laws in the United States, Biodexa does not undertake any obligation to publicly update or revise any forward-looking statements because of new information, future events or events otherwise arising.