On November 17, 2025 Accession Therapeutics Limited, a biopharmaceutical company developing next generation cancer immunotherapies, reported it has dosed the first patient in its Phase I clinical trial evaluating TROCEPT-01 (ATTR-01), the company’s lead drug candidate from its proprietary TROCEPT platform technology. The patient has now completed the cycle of treatment. This milestone marks a major step forward in the development of a potentially transformative treatment for solid tumours.

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TROCEPT-01 (ATTR-01) is a first-in-class, tumour-activated viral immunotherapy that, following systemic delivery, is designed to selectively generate a clinically validated checkpoint inhibitor within tumours. This approach, targeting αvβ6 integrin on epithelial tumours, optimises efficacy while minimising damage to healthy tissue. Preclinical studies have demonstrated strong anti-tumour activity across multiple solid tumour models, supporting its potential as a targeted therapy for aggressive cancers.

The ATTEST trial is an open label, dose-escalation and dose expansion study (View Source) designed to evaluate the safety, tolerability, pharmacokinetics, and preliminary efficacy of TROCEPT-01 (ATTR-01) in patients with advanced carcinomas who have had at least one prior treatment course. The trial is being conducted at leading clinical sites across the UK. Additional trial sites will be activated as the study progresses, including in Spain where there is established expertise in the treatment of solid tumours.

Professor Adel Samson, Professor of Cancer Medicine and Immunotherapy at Leeds University School of Medicine and lead Investigator in the ATTEST study, said:
"As a clinician, I am very excited about the potential of TROCEPT-01 (ATTR-01) and the TROCEPT platform to increase clinical response rates through high tumour-localised production of anti-cancer drugs. This program is targeted at solid tumours where there is significant need for better treatment outcomes".

Bent Jakobsen, PhD FMedSci, CEO of Accession Therapeutics, said:
"Dosing the first patient in our TROCEPT-01 clinical trial is a pivotal moment for Accession Therapeutics and a testament to the dedication of our team and collaborators. In TROCEPT, we have created a unique, highly versatile platform that enables novel drugs to be made inside cancer cells. The platform gives us multiple opportunities to generate valuable products to transform outcomes for cancer patients. TROCEPT-01 (ATTR-01) has the potential to expand the indications where checkpoint inhibitors have been successful."

Professor Hardev Pandha, FRCP, FRACP, PhD, Medical Director of Accession Therapeutics, added:
"TROCEPT-01 (ATTR-01) represents a novel approach to target hard-to-treat cancers, and we are excited to advance this promising therapy into clinical development. We anticipate the clinical data will show that the virus gets to the tumours when given systemically, and that the drug is produced within the tumours. Our goal in the ATTEST study is to establish a strong safety profile while identifying early signals of efficacy to benefit patients with limited treatment options."

(Press release, Accession Therapeutics, NOV 17, 2025, View Source [SID1234660037])