Clinical Trial of SYS6010±SYH2051 Versus Chemotherapy in Advanced Breast Cancer and Other Solid Tumors

Phase Ⅰb Design: Group A (SYS6010 3.2 mg/kg, Q2W): Monotherapy Cohort: Planned enrollment of 8-12 breast cancer patients to evaluate the safety and preliminary efficacy of SYS6010 monotherapy. Combination Cohort: Includes dose-escalation and expansion phases. Dose-escalation phase: A "3+3" design will be used to explore the safety of SYS6010 combined with SYH2051, with SYH2051 doses ranging from 60-80 mg. Expansion phase: Upon completion of dose-escalation and confirmation of safety, breast cancer patients may be enrolled in the expansion phase. Group B (SYS6010 3.6 mg/kg, Q2W): Monotherapy Cohort: Planned enrollment of 8-12 breast cancer patients. Combination Cohort: Similar to Group A, with SYH2051 doses ranging from 40-60 mg. Group C (SYS6010 3.6 mg/kg, Q2W): Enroll 40 EGFR-expressing HR+/HER2- breast cancer patients to further evaluate the safety and efficacy in this specific population. Phase Ⅱ Design: Based on molecular subtypes of breast cancer, cohort studies will be conducted. Each cohort will enroll 125 patients, randomized in a 2:2:1 ratio into three groups: SYS6010 + SYH2051 SYS6010 monotherapy Chemotherapy control.