1378TiP - A phase I clinical trial investigating the therapeutic cancer vaccine UV1 in combination with pembrolizumab as first-line treatment of patients with malignant melanoma

Abstract

BackgroundThis ongoing trial is investigating the safety and efficacy of combining the therapeutic cancer vaccine UV1 with the anti-PD-1 mAb pembrolizumab. UV1 is a peptide-based vaccine directed against telomerase, an essential enzyme for unlimited cell-division and a hallmark of cancer. Due to its selective expression, telomerase serves as a unique cancer antigen. UV1 consists of 3 long peptides (15-30 aa) representing fragments of the reverse transcriptase subunit of telomerase (hTERT). The peptides contain both CD4 and CD8 epitopes and are shown to be immunogenic in 78% of HLA unselected patients across different cancer types. UV1 induces hTERT-specific tumor-reactive T cells, and has the potential to induce epitope spreading. UV1 can increase the efficacy of checkpoint inhibitors in patients with insufficient numbers of T cells spontaneously primed by tumor antigens. Reciprocally, the efficacy of UV1 may be enhanced by checkpoint inhibitors, since the effector activity of UV1-induced T cells will be restricted by intrinsic and tumor-induced suppressor mechanisms. UV1 and pembrolizumab thus have the potential to produce synergistic immunological activity which may provide increased clinical benefit as compared to pembrolizumab alone. Trial designThe ongoing phase I, open-label, multicenter study is planned to include 20 patients with untreated unresectable or metastatic melanoma. UV1 (300μg) with GM-CSF (37,5μg) as adjuvant is administered intradermally for a total of 8 doses, 3 doses during week 1, and one dose during week 2, 3, 8, 11 and 14. Pembrolizumab is administered every third week starting week 2 for up to two years or until progressive disease. Patients are followed for up to 2 years after the first UV1 dose. The primary objective of the study is to evaluate the safety and tolerability of the UV1 and pembrolizumab therapy. Secondary objectives are UV1 vaccine-specific immune responses and evaluation of tumor response (RECIST). Samples of blood, feces, and tumor tissue are collected for translational research purposes. Clinical trial identificationNCT03538314. Legal entity responsible for the studyUltimovacs AS. FundingUltimovacs AS. DisclosureY. Zakharia: Advisory / Consultancy: Amegen; Advisory / Consultancy: Roche Diagnostics; Advisory / Consultancy: Novartis; Advisory / Consultancy: JNJ; Advisory / Consultancy: Eisai; Advisory / Consultancy: Exelixis; Advisory / Consultancy: Castle Bioscience; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Bayer; Advisory / Consultancy: Array. All other authors have declared no conflicts of interest.