Sequential ipilimumab (Ipi) versus best supportive care (BSC) following first-line chemotherapy (Ctx) in patients (pts) with unresectable locally advanced or metastatic gastric or gastro-esophageal junction (GEJ) cancer: A randomized, open-label, two-arm, phase II trial (CA184-162) of immunotherapy as a maintenance concept.

TPS4151 Background: First-line systemic CTX is standard-of-care for advanced gastric cancer. However, most pts relapse or have severe adverse events (AEs), creating a need for new therapies with better benefit/risk and toxicity profiles. Endogenous immune activity against tumor cells has been demonstrated in the human gastric cancer tumor microenvironment, supporting a role for immunotherapy. As a new maintenance concept, sequential administration of immunotherapy may prolong clinical benefit of first-line CTX before disease progression (PD). Ipi, a fully human monoclonal antibody which binds CTLA-4, augments the antitumor immune response. Ipi improved overall survival (OS) in patients with advanced melanoma with AEs managed using product-specific treatment guidelines.This global (32 sites among 10 countries), multicenter, randomized, open-label, phase II trial (ClinicalTrials.gov identifier NCT01585987) will compare the efficacy of Ipi and BSC after first-line CTX. Methods: Pts with good performance stat...