Mendus AB announced the presentation of new clinical data from the Phase 1 ALISON ovarian cancer trial at the American Association for Cancer Research (AACR) Annual Meeting 2023. The data presented at AACR demonstrate that vididencel treatment is safe, well-tolerated and induces durable T-cell responses to tumor associated antigens in ovarian cancer patients. At the time of the data cut (March 17, 2023) 11 patients were enrolled in the trial, of which 7 had completed vididencel vaccination and 4 were still on treatment.

In total 4 patients had recurred, of which one died. Immune responses were evaluated in 5 patients and 4 patients demonstrated durable vaccine-induced T cell responses (VIR) against at least one tumor-associated antigen. The 1 patient not showing a VIR already had high base line responses against all four antigens measured.

Thus far, vididencel showed only mild to moderate adverse events after intradermal administration. In all patients, an injection site reaction was observed, which resolved over a few days, confirming the intradermal immune response induced. Combined, the data presented at AACR show that vididencel is capable of inducing durable T cell responses against tumor associated antigens previously shown to be relevant in ovarian cancer and continues to be safe and well tolerated.

Based on the initial positive data, the ALISON study will continue to enroll new patients. The Phase 1 ALISON trial (NCT04739527) is a single-center, open-label trial evaluating safety and efficacy of vididencel (DCP-001) in High-Grade Serous Ovarian Cancer (HGSOC) patients. Treatment of HGSOC after debulking and chemotherapy remains challenging, due to a high risk of chemotherapy remains challenging, due to a high risk of chemotherapy resistance and disease relapse.

The ALISON trial evaluates the use of vididencel as a maintenance immunotherapy, aimed to prolong disease-free survival following primary treatment. The primary endpoint of the trial is the number of patients with vididencel induced antigen-specific T cells responses in peripheral blood after treatment. Key secondary endpoints include safety and tolerability after repeated vididencel dosing, as well as recurrence free survival (RFS) and overall survival (OS) during a 2-year follow-up period.

Patient enrolment and further analysis of vididencel induced immune responses will continue in 2023.