osemitamab + pembrolizumab + capecitabine + oxaliplatin

A combination regimen consisting of osemitamab (TST001), pembrolizumab (Keytruda), and chemotherapy (either CAPOX: capecitabine and oxaliplatin; or FOLFOX: 5-fluorouracil, leucovorin, and oxaliplatin). Osemitamab is a second-generation, humanized IgG1 monoclonal antibody targeting Claudin 18.2 (CLDN18.2), a tight junction protein frequently overexpressed in gastric and gastroesophageal junction (G/GEJ) adenocarcinomas. It is engineered with a fucose-reduced Fc region to enhance its binding to FcγRIIIa on natural killer cells, thereby increasing antibody-dependent cellular cytotoxicity (ADCC). Pembrolizumab is a PD-1 inhibitor that prevents the interaction between PD-1 and its ligands (PD-L1 and PD-L2), reactivating the anti-tumor immune response. The chemotherapy components (oxaliplatin and a fluoropyrimidine) provide direct cytotoxic activity. This triplet combination is currently being evaluated in a Phase 3 trial (NCT06093425) as a first-line treatment for patients with CLDN18.2-positive, HER2-negative advanced or metastatic G/GEJ adenocarcinoma.

Brand names

Keytruda

Other names

osemitamab + pembrolizumab + oxaliplatin + leucovorin + fluorouracilTST001 + pembrolizumab + CAPOXTST001 + pembrolizumab + FOLFOXKeytruda + capecitabine + oxaliplatin or Keytruda + oxaliplatin + leucovorin + 5-fluorouracil