A Study of TAS0728 in Patients With Solid Tumors With HER2 or HER3 Abnormalities

This is a First-in-Human (FIH), 2-part, Phase 1/2, open-label, multicenter study design to evaluate the safety, tolerability, PK, pharmacodynamics, PGx, and efficacy of TAS0728. This study consists of Phase 1 and Phase 2 components in subjects with advanced solid tumors with HER2 or HER3 overexpression, amplification, or mutation who have progressed despite standard therapy or for which no standard therapy exists, particularly urothelial cancer, biliary tract cancer, metastatic breast cancer, non-small cell lung cancer and colorectal cancer.