Advanced Solid Tumors With MTAP Deletion

This is a multicenter, single-arm, open-label, dose-escalation, dose-expansion study to evaluate the safety, tolerability, PK/PD, and preliminary anti-tumor activity of GH56 Capsule in subjects with advanced solid tumors who have failed or are intolerant to standard treatment, or have no standard therapy. The clinical trial will be carried out in two parts: phase Ia study (dose escalation study) and phase Ib (dose expansion study).The Part Ib dose expansion study includes adult cohort and adolescent cohort (12-17 years of age).