A Phase 1/2a, Multicenter, Open-Label, First in Human Study to Assess the Safety, Tolerability, Pharmacokinetics, and Preliminary Antitumor Activity of DB-1310 in Subjects With Advanced/Metastatic Solid Tumors

This is a multicenter, open-label, multiple-dose, FIH Phase 1/2a study. Phase 1 adopts the standard "3+3" design to identify: the MTD and/or RP2D of DB-1310 as monotherapy, the RCD\_A of DB-1310 in combination with trastuzumab or approved trastuzumab biosimilar and the RCD\_B of DB-1310 in combination with Osimertinib; Phase 2a is a dose expansion phase to confirm the safety, tolerability and explore efficacy in selected malignant solid tumors treated with DB-1310 as monotherapy or in combination with trastuzumab or approved trastuzumab biosimilar or in combination with Osimertinib, or in comb…