Evaluate the Safety, Tolerability, Pharmacokinetics and Efficacy of BL-M05D1 in Subjects With Solid Tumors

This is a multicenter Phase 1, open-label study to evaluate the safety, tolerability, pharmacokinetic profile, and initial efficacy of BL-M05D1 in subjects with unresectable locally advanced or metastatic solid tumors that are known to potentially express CLDN18.2, including but not limited to gastric and gastroesophageal junction adenocarcinoma (G/GEJ AC), esophageal AC (EAC), pancreatic ductal AC (PDAC), and biliary tract cancer (BTC). Participants must have recurred or progressed on at least 1 line of prior systemic therapy (including adjuvant/neoadjuvant), have no other standard of care options, and have no available curative options. This study will be conducted in three parts (dose escalation, dose finding and dose expansion). Subjects will be dosed on Day 1 of a continuous 21-day treatment cycle.