Phase 1 Study of FS-1502 in Patients With HER2 Expressed Advanced Solid Tumors and Breast Cancer.

"Dose-Escalation Phase (Phase 1a)： FS-1502 dose-escalation will be proceeded on standard 3+3 design with starting dose of 0.1 mg/kg, IV, once per 28 days, 28 days as a cycle in the V1.2 and V2.0 regimens; IV, once per 21 days, 21 days as a cycle in the V3.0 regimens..~Dose level 1: 0.1 mg/kg; Dose level 2: 0.2 mg/kg; Dose level 3: 0.4 mg/kg; Dose level 4: 0.6 mg/kg; Dose level 5: 0.8 mg/kg; Dose level 6: 1.0 mg/kg; Dose level 7: 1.3 mg/kg. If 1.3mg/kg is still tolerated safely and in line with linear kinetic characteristics, and combined with the results of PK, PD, safety and effectiveness, a comprehensive assessment is made to determine whether to continue the dose escalating. The subsequent dose increase ratio is 33% (the dose increase ratio can be adjusted according to the previous data results) until MTD or RP2D.~Dose-expansion Phase (Phase 1b) : RP2D determined in phase 1a, IV."