Astellas Pharma initiated a Phase 3 clinical trial for its investigational bispecific antibody ASP2138, designed to target CLDN18.2-positive gastric and gastroesophageal junction cancers. The randomized, double-blind, placebo-controlled study will enroll 570 adults with locally advanced unresectable or metastatic adenocarcinoma whose tumors express CLDN18.2 but lack HER2 expression.
Participants will receive ASP2138 in combination with chemotherapy and pembrolizumab as a first-line treatment, with the regimen compared against a placebo plus chemotherapy with or without pembrolizumab. The trial’s co-primary endpoints are overall survival and progression-free survival, with results expected to benchmark against the current standard of care, which typically achieves a median progression-free survival of six to seven months in non-CLDN18.2-targeted regimens.
The study, registered under ClinicalTrials.gov as NCT07673887, aligns with Astellas’s Corporate Strategic Plan, which aims to initiate five or more Phase 3 or pivotal trials by fiscal year 2027. Tadaaki Taniguchi, Astellas’s Chief Research and Development Officer, highlighted the first patient dosing as a significant milestone for ASP2138 and the company’s broader CLDN18.2 program.
