59P - Long term survival data from all recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) patients treated with MVX-ONCO-1 during open-labelled phase I and phase IIa clinical trials

Background

MVX-ONCO-1 is a personalized cancer immunotherapy combining irradiated autologous tumor cells as a tailored source of antigen and cell encapsulation technology to deliver GM-CSF, a potent adjuvant, in a sustained manner. MVX-ONCO-1 Phase IIa met its primary endpoint with 68.8% patients (pts) alive at 6 months (mos). Updated median Overall Survival (OS) is 12 mos with complete and partial responses and evidence of immune education highlighted by positive Delayed Type Hypersensitivity, T and B cells responses. Safety and feasibility were assessed without any safety signals or manufacturing issues.

Methods

We analyze all 18 R/M HNSCC pts treated with MVX-ONCO-1. All had progressive disease after at least 1 line of systemic therapy, with measurable disease and ECOG PS 0-2. 15/18 pts received anti-pd-1 immunotherapy and were exposed to more than 2 lines of therapy.

Results

1 pt was lost to follow up (>14 mos), 5/17 (29.4%) are alive after 2 years and 4/16 (25%) after 3 years including 3 complete responses and 4 partial responses. To date, one pt is alive more than 7 years without any anticancer therapy and no evidence of disease. Another showed stable disease upon MVX-ONCO-1 therapy and subsequently presented a complete response upon nivolumab immunotherapy despite a PD-1 negative tumor. Based on 17 pts, median and mean survival are 21.7 mos and 33.2 mos respectively from the initiation of anti-pd-1 immunotherapy.

Conclusions

MVX-ONCO-1 is the first cancer vaccine with single agent activity, associated with prolonged survival in advanced chemotherapy / Immunotherapy refractory metastatic HNSCC without maintenance therapy. To date, second line treatment with pembrolizumab (Keynote 040) lead to 19% OS at 3 years with a median OS of 8.4 mos. First line treatment with chemotherapy / pembrolizumab (Keynote 048) shows 22% OS at 3 years and median OS of 13 mos. Data on all R/M HNSCC heavily pretreated pts treated with MVX-ONCO-1 demonstrates positive survival, with 25% of pts alive after 3 years, and median OS from start of immunotherapy reaching 21.7 mos.

Clinical trial identification

NCT02193503; NCT02999646.

Legal entity responsible for the study

Swissmedic, Geneva Ethic Committee.

Funding

EC | Horizon 2020 Framework Programme (EU Framework Programme for Research and Innovation H2020) - 880194 [Mach] Gateway for Cancer Research (Gateway) - G-15-1700 [Mach] Krebsliga Schweiz (Ligue Suisse Contre le Cancer) - KLS-3867-02-2016 [Mach] Rising Tide Foundation for Clinical Cancer research (CCR-15-140), Innosuisse (CTI), Fondation Coromandel, Philanthropy Settlement, MaxiVAX [Mach].

Disclosure

N. Mach: Financial Interests, Personal, Stocks or ownership: MaxiVAX SA. E. Charrier, J. Grogg, J. Renaux: Financial Interests, Personal, Full or part-time Employment: MaxiVAX SA. O.A. Michielin: Financial Interests, Institutional, Invited Speaker: BMS, Amgen, Pierre Fabre, Roche; Financial Interests, Institutional, Writing Engagement: BMS; Financial Interests, Institutional, Advisory Board: BMS, Amgen, Roche, Novartis, Pierre Fabre, MSD; Financial Interests, Personal, Other, Advisory Role: BMS, MSD, Roche, Novartis, Pierre Fabre, Amgen, GSL; Financial Interests, Personal, Advisory Board, Member of the Scientific Board of Cellula Therapeutics: Cellula Therapeutics; Financial Interests, Personal, Stocks/Shares: Cellula Therapeutics; Financial Interests, Institutional, Research Grant: BMS, MSD, Pierre Fabre, Amgen, Merck; Financial Interests, Institutional, Funding: BMS, MSD, Pierre Fabre, Amgen, MSD; Non-Financial Interests, Personal, Principal Investigator: BMS, MSD, Amgen, Roche, Pierre Fabre, Novartis. All other authors have declared no conflicts of interest.