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."

About Prostate Cancer

In 2020, prostate cancer was the fourth most common cancer worldwide, with 1.4 million new cases diagnosed.⁴ In the US, out of every 100 American men, about 13 will get prostate cancer during their lifetime.⁵ In the UK, prostate cancer is the most common cancer in men, with more than 52,000 people diagnosed with the disease on average each year.⁶ 20-30% of patients experience rising levels of PSA after local therapy (e.g. prostatectomy), indicating that disease was not cured by local therapy.⁷ Of men who do experience biochemical recurrence, there is a 1 in 9 chance of developing metastases.⁸

About Vaccitech

Vaccitech is a clinical-stage biopharmaceutical company focused on the development of novel T cell immunotherapeutics designed to harness the power of the immune system to treat and cure chronic infectious diseases, autoimmune diseases, and cancer. The Company stands apart through a proprietary, multi-platform approach that has shown the ability to induce higher magnitudes of T cells compared with other technologies. Vaccitech is uniquely positioned to address the needs of large, underserved patient populations through a diverse clinical-stage pipeline of investigational therapies targeting diseases that pose significant public health risk and have limited treatment options. The Company's lead product candidates include VTP-300, an immunotherapy product candidate designed as a component of a potential functional cure for chronic hepatitis B viral (HBV) infection; VTP-200, a non-invasive, early-stage investigational treatment for persistent, high-risk human papillomavirus (HPV) infection; VTP-850, a novel T cell investigational therapy for prostate cancer; and VTP-1000, a preclinical T cell therapeutic candidate designed to restore immune tolerance in celiac disease. Vaccitech has proven drug development and scientific expertise in the field of immunization, co-inventing a COVID-19 vaccine with the University of Oxford, which is now approved and exclusively licensed worldwide to AstraZeneca.

For more information, visit www.vaccitech.co.uk.

Forward Looking Statements

This press release contains forward-looking statements, within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, which can generally be identified as such by use of the words "may," "will," "plan," "forward," "intend," "promising," "believe," "potential," and similar expressions, although not all forward-looking statements contain these identifying words. These forward-looking statements include, without limitation, express or implied statements regarding: the Company's plans and strategy with respect to VTP-850 and the PCA001 clinical trial, including plans for patient enrollment in Italy and Spain, the potential benefits of VTP-850 for the treatment of prostate cancer and expected patient population of VTP-850. Any forward-looking statements in this press release are based on management's current expectations and beliefs and are subject to numerous risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, risks and uncertainties related to the success, cost and timing of the Company's product development activities and planned and ongoing clinical trials, the Company's ability to execute on its strategy, regulatory developments, the Company's ability to fund its operations, global economic uncertainty, including disruptions in the banking industry, the impact that the COVID-19 pandemic may have on the Company's clinical trials and preclinical studies, and access to capital and other risks identified in the company's filings with the Securities and Exchange Commission (the "SEC"), including its Annual Report on Form 10-K for the year ended December 31, 2022, its Quarterly Reports on Form 10-Q and subsequent filings with the SEC. The Company cautions you not to place undue reliance on any forward-looking statements, which speak only as of the date they are made. The Company expressly disclaims any obligation to publicly update or revise any such statements to reflect any change in expectations or in events, conditions or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements.

References

1. Cappuccini. F, et al, J Immunother Cancer, 2020. DOI: 10.1136/jitc-2020-000928
2. Tuthill, M, et al, Ann. Oncol. 2020. DOI: https://doi.org/10.1016/j.annonc.2020.08.2076
3. Artibani, W, et al, Urol Int, 2017. DOI: https://doi.org/10.1159/000481438
4. WHO, Cancer, 2022.
5. CDC, Prostate Cancer, 2022.
6. Prostate Cancer UK, About Prostate Cancer, 2022.
7. Johns Hopkins Medicine, Prostate Cancer Prognosis, 2023.
8. Stensland. KD, et al, J Clin Onc, 2022. DOI: 10.1200/JCO.2022.40.16_suppl.5090