Vaccitech Doses First Patient in PCA001, a Prostate Cancer Phase 1/2 Clinical Trial of VTP-850 Immunotherapeutic Candidate in Men with Rising PSA after Definitive Local Therapy

OXFORD, United Kingdom, June 12, 2023 (GLOBE NEWSWIRE) -- Vaccitech plc (NASDAQ: VACC) (the Company, we or us), a clinical-stage biopharmaceutical company engaged in the discovery and development of novel immunotherapeutics for the treatment of autoimmunity, chronic infectious diseases and cancer, today announced the dosing of the first patient in the PCA001 clinical trial (NCT05617040). PCA001 is a multi-centre, Phase 1/2 clinical trial designed to determine the recommended Phase 2 regimen and evaluate the safety, efficacy, as measured by prostate-specific antigen (PSA) response, and T cell response of VTP-850 monotherapy in men with rising PSA after definitive local therapy for their disease (i.e., biochemical recurrence).

VTP-850 is a next-generation prostate cancer immunotherapeutic candidate which utilizes Vaccitech’s sequential dosing approach of two proprietary nonreplicating viral vectors, ChAdOx and MVA. PCA001 builds on the previous promising data from the University of Oxford VANCE01 (NCT02390063) and ADVANCE (NCT03815942) trials, Phase 1 and Phase 1/2 clinical trials respectively, of VTP-800, the first-generation product candidate which encoded 5T4, an antigen expressed by most prostate cancers.^1,2 VTP-850 is a multi-antigen immunotherapeutic candidate containing four prostate-associated antigens: PSA, PAP, STEAP1 and 5T4. The first phase of the trial is enrolling participants in the US, with plans to open further sites in Italy and Spain.

“20-40% of patients will unfortunately experience biochemical recurrence following initial local therapy for prostate cancer with the potential to experience metastases.³ VTP-850 is our next-generation, multi-antigen product candidate designed to induce a targeted polyclonal T cell response to kill remaining tumor cells and prevent advancement to metastatic disease,” said Bill Enright, Chief Executive Officer of Vaccitech. “We saw very encouraging data from the VANCE01 and ADVANCE trials, and we are excited to begin PCA001 where VTP-850 will be evaluated as a monotherapy in a patient population with important unmet medical needs.”

“VTP-850 encodes four prostate cancer antigens and is designed to induce a broader T cell response to tumor cells,” said Dr. Meg Marshall, Chief Medical Officer of Vaccitech. “When the immune system targets multiple molecules on tumor cells, it is generally harder for tumor cells to escape destruction by the immune system.”