Core Viewpoint - The article discusses the promising potential of CLDN18.2 as a therapeutic target for gastric and gastroesophageal junction adenocarcinoma, highlighting the development and clinical trial results of the antibody-drug conjugate (ADC) IBI343 [1][4][9]. Group 1: IBI343 Overview - IBI343 is an ADC developed by Innovent Biologics, consisting of a fully humanized anti-CLDN18.2 monoclonal antibody, a DNA topoisomerase I (TOP-1) inhibitor, and a cleavable linker, with a drug-to-antibody ratio of 4 [2]. - The clinical trial results published in Nature Medicine indicate that IBI343 shows good tolerability and manageable safety, with a low incidence of gastrointestinal adverse events in patients with high CLDN18.2 expression [3][4]. Group 2: Clinical Trial Results - A total of 127 patients with advanced gastric or gastroesophageal junction adenocarcinoma were enrolled in the phase 1 trial, with 19 in the dose escalation phase and 108 in the dose expansion phase [7]. - At a dose of 10 mg/kg, 2 out of 6 participants experienced dose-limiting toxicities, including one case of grade 4 bone marrow suppression and one case of grade 4 neutropenia [8]. - The recommended phase 2 dose is 6 mg/kg every 3 weeks, showing an objective response rate of 29% and a median progression-free survival of 5.5 months in patients with high CLDN18.2 expression [9]. Group 3: Future Research Directions - Ongoing phase 3 multicenter, randomized, controlled studies and future research on the combination of IBI343 with other therapies, particularly immunotherapies, may provide further evidence supporting IBI343 as a new treatment option for gastric and gastroesophageal junction adenocarcinoma and other CLDN18.2-expressing solid tumors [10][11].