674PD - Perioperative FLOT + anti-PD-L1 avelumab (FLOT-A) chemo-immunotherapy in resectable oesophagogastric adenocarcinoma (OGA): Safety and biomarker data from the ICONIC trial safety run-in

Abstract

BackgroundICONIC is a single arm phase 2 trial investigating the safety and efficacy of 4 cycles pre-operative and 4 cycles post-operative FLOT-A in resectable OGA. We report results from the safety run-in phase and early translational biomarker data. MethodsEligible pts were enrolled into the 3+3 design dose finding stage. Standard dose FLOT was administered with 10mg/kg iv avelumab q2 weeks (dose level 0). Dose limiting toxicities (DLTs) were assessed for 28d. Biopsies were taken at baseline and post cycle 2. ResultsAt data cut-off (12/4/19) 6 pts were enrolled and completed pre-operative treatment. 1/6 pts experienced a DLT (chest pain during 5FU infusion), and dose level 0 was established as the safe dose for the efficacy stage of the trial. During pre-operative FLOT-A all pts experienced at least one grade 1-2 adverse event (AE), most commonly diarrhoea (5/6 pts), fatigue, nausea, peripheral neuropathy and hypokalaemia (all 4/6 pts); 3/6 pts experienced at least one grade 3-4 AE: neutropenia and elevated liver enzymes (1pt), thrombotic event (1pt) and cardiac chest pain (1pt). 4/6 pts reported any grade chest pain and underwent cardiac work up: 1 episode was due to PE, 1 of likely GI origin and 2 cardiac in nature, which then recurred in one pt who was re-exposed to FLOT without avelumab. 3/6 pts completed 4 cycles pre-operative FLOT-A: 1pt discontinued avelumab due to diarrhoea, 2 pts discontinued FLOT-A due to cardiac chest pain and switched to a regimen without 5FU. 5 pts have undergone surgery at data cut-off, without unexpected complications. Immunofluorescence shows changes of CD8-, memory- and regulatory T cell infiltrates between baseline and on-treatment biopsies, and detailed results will be presented. ConclusionsThis is the first data showing that FLOT can be combined with a PD-L1-inhibitor with FLOT-A having a manageable safety profile at dose level 0 (standard dose FLOT + 10mg/kg avelumab). As chest pain of variable aetiologies was observed in 4/6 patients this will be closely monitored and assessed during the efficacy phase. No unexpected complications have been observed during surgery following FLOT-A treatment. Clinical trial identification2016-003306-13. Legal entity responsible for the studyRoyal Marsden Hospitals NHS Foundation Trust. FundingRoyal Marsden Hospital NHS Foundation Trust Institute of Cancer Research, Merck Pharmaceuticals. DisclosureM. Davidson: Travel / Accommodation / Expenses: Celgene. N. Starling: Research grant / Funding (institution): AstraZeneca; Research grant / Funding (institution): BMS; Research grant / Funding (institution): Merck; Honoraria (institution): AstraZeneca. I. Chau: Advisory / Consultancy: Eli-Lilly; Advisory / Consultancy: BMS; Advisory / Consultancy: MSD; Advisory / Consultancy: Bayer; Advisory / Consultancy: Roche; Advisory / Consultancy: Merck-Serono; Advisory / Consultancy: Five Prime Therapeutics; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy: Oncologie International; Advisory / Consultancy: Pierre Fabre; Research grant / Funding (institution): Eli-Lilly; Research grant / Funding (institution): Janssen Cilag; Research grant / Funding (institution): Sanofi Oncology; Research grant / Funding (institution): Merck-Serono; Honoraria (institution): Eli-Lilly. D. Cunningham: Research grant / Funding (institution): Amgen; Research grant / Funding (institution): AstraZeneca; Research grant / Funding (institution): Bayer; Research grant / Funding (institution): Celgene; Research grant / Funding (institution): Merck-Serono; Research grant / Funding (institution): Medimmune; Research grant / Funding (institution): Merrimack; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): Roche; Research grant / Funding (institution): Sanofi. D. Morganstein: Advisory / Consultancy: MSD; Advisory / Consultancy: BMS; Advisory / Consultancy: Roche. M.D. Forster: Research grant / Funding (institution): Merck; Honoraria (institution): Merck. M. Gerlinger: Research grant / Funding (institution): Merck; Research grant / Funding (institution): BMS. All other authors have declared no conflicts of interest.