LM-302 + tegafur + gimeracil + oteracil potassium

LM-302 + tegafur + gimeracil + oteracil potassium is an experimental combination therapy composed of LM-302, a CLDN18.2-targeted antibody-drug conjugate (ADC), and the oral fluoropyrimidine S-1 (itself a fixed-dose combination of tegafur, gimeracil, and oteracil potassium) used in investigational settings for treating advanced or refractory gastric and gastroesophageal junction (GEJ) adenocarcinoma. - **LM-302** is an ADC consisting of a recombinant humanized anti-CLDN18.2 IgG1 monoclonal antibody (LM-102) conjugated to monomethyl auristatin E (MMAE), a microtubule inhibitor. LM-302 binds selectively to CLDN18.2-expressing tumor cells, is internalized, and releases MMAE, leading to cell cycle arrest and apoptosis. - **Tegafur** is a prodrug of 5-fluorouracil (5-FU), interfering with DNA synthesis. - **Gimeracil** inhibits dihydropyrimidine dehydrogenase (DPD), thereby increasing the systemic bioavailability of 5-FU. - **Oteracil potassium** reduces gastrointestinal toxicity by inhibiting phosphorylation of 5-FU in the gut. This combination aims to leverage direct cytotoxic, targeted, and chemotherapeutic mechanisms against advanced gastrointestinal tumors, especially those expressing CLDN18.2[1][2][4][5].