First-line osemitamab (TST001) plus nivolumab and CAPOX for advanced G/GEJ cancer (TranStar102): Updated results of cohort G from a phase I/IIa study.

作者：Jifang Gong, Dan Liu, Zengqing Guo, Jingdong Zhang, Weijian Guo, Meili Sun, Nong Xu, Chuan Qi, Lijuan Zhang, Zhenzhong Xia, Jianming Wang, Li Xu, Caroline Germa, Lin Shen · 发表于：Journal of Clinical Oncology · 年份：2025 · DOI：10.1200/jco.2025.43.16_suppl.4032 · 被引用次数：10 · 研究领域：Peptidase Inhibition and Analysis、Neuroendocrine Tumor Research Advances、Pancreatic and Hepatic Oncology Research

4032 Background: Claudin 18.2 (CLDN18.2) is a clinically validated therapeutic target and has been broadly explored with different modalities in gastric/gastroesophageal (G/GEJ) cancer treatment. Osemitamab is a humanized monoclonal antibody with improved affinity to CLDN18.2, reduced fucosylation and enhanced ADCC activity and has been observed to upregulate PD-L1 expression on CLDN18.2-positive tumor cells. In vivo anti-tumor activity of combination of osemitamab plus an anti-PD-1/PD-L1 antibody and chemotherapies was significantly stronger than any of the doublet combinations, regardless of the PD-L1 CPS levels, making the triple combination of osemitamab, nivolumab and CAPOX an attractive combination to explore. Methods: Cohort G from TranStar102 (NCT04495296, a phase I/II study) was designed to evaluate the safety and preliminary efficacy of osemitamab at two dose levels (3mg/kg or 6mg/kg Q3W) plus nivolumab and CAPOX as the first-line treatment in patients with G/GEJ cancer. 40 patients were planned to be enrolled in each dose level. Key eligible criteria included HER2 negative or unknown, unresectable locally advanced or metastatic G/GEJ cancer, regardless of CLDN18.2 or PD-L1 expression and treatment naïve for advanced disease. The endpoints include safety, efficacy, PK and predictive value of the different levels of CLDN18.2 expression, etc. Results: As of Jan 13, 2025, 82 patients were dosed with osemitamab plus nivolumab and CAPOX (40 at 3mg/kg, 42 at 6mg/kg) with ...