KM257 + gemcitabine + carboplatin

KM257 + gemcitabine + carboplatin is a **combination regimen** investigated in patients with advanced HER2-positive or HER2-expressing solid tumors. **KM257** is a bispecific antibody targeting HER2, binding HER2 domain II and domain IV, and acts as a receptor tyrosine-protein kinase erbB-2 (HER2) antagonist to block HER2-mediated cellular signaling pathways critical for tumor growth and survival[3][5]. **Gemcitabine** is a nucleoside analog chemotherapeutic that inhibits DNA synthesis by masked chain termination and ribonucleotide reductase blockade, leading to cell cycle arrest and apoptosis[2]. **Carboplatin** (though not directly detailed in results, is analogous to cisplatin) is a platinum-based agent that cross-links DNA, causing cell cycle arrest and apoptosis[2]. The combination is being tested to leverage synergistic antitumor effects. Xuanzhu Biopharmaceutical is developing KM257; the drug combination is currently being studied in phase 1 trials for advanced neoplasms[1][3][5].