Fast: An International, Multicenter, Randomized, Phase Ii Trial Of Epirubicin, Oxaliplatin, And Capecitabine (Eox) With Or Without Imab362, A First-In-Class Anti-Cldn18.2 Antibody, As First-Line Therapy In Patients With Advanced Cldn18.2+Gastric And Gastroesophageal Junction (Gej) Adenocarcinoma.

LBA4001Background: Claudin18.2 (CLDN18.2) is a tight junction protein expressed by several cancers including gastric and GEJ adenocarcinoma. IMAB362 is a chimeric monoclonal antibody that mediates specific killing of CLDN18.2-positive cancer cells by activation of immune effector mechanisms. IMAB362 has demonstrated single-agent activity and was safe and tolerable in patients (pts) with pretreated gastric cancer. Methods: Pts with advanced/recurrent gastric and GEJ cancer were centrally evaluated for CLDN18.2 expression by IHC (validated CLAUDETECT18.2 Kit). Eligible pts had a CLDN18.2 expression of ≥ 2+ in ≥ 40% tumor cells, an ECOG PS of 0–1 and were not eligible for trastuzumab. Pts were randomized 1:1 to first-line EOX (epirubicin 50 mg/m2 and oxaliplatin 130 mg/m2 d1, and capecitabine 625 mg/m2 bid, d1–21; qd22) with or without IMAB362 (loading dose 800 mg/m2, then 600 mg/m2 d1, qd21). The study was extended by an exploratory Arm3 (N = 85) to investigate a high dose IMAB362 (1000 mg/m2) plus EOX, (no...