This is a phase 2, open-label, multi-center study consisting of two parts: Phase 2a and 2b.~Phase 2a: The study will be conducted in the following two cohorts: Cohort 1: Patients with advanced osteosarcoma upon disease progression after standard treatment. Cohort 2: Patients with other unresectable bone and soft tissue sarcomas, if they have progressed on or intolerant to available standard therapies, or no standard or available curative therapy exists. Subjects will be randomly assigned in a 1:1 ratio to 8.0 mg/kg and 12.0 mg/kg of HS-20093 in cohort 1 and will receive 12.0 mg/kg in cohort 2.~Phase 2b: The study will be conducted in patients with advanced osteosarcoma upon disease progression after standard treatment. Subjects will receive HS-20093 at the recommended dose from Phase 2a.~All patients will be carefully followed for adverse events during the study treatment and for 90 days after the last dose of HS-20093. Subjects will be permitted to continue therapy with assessments for progression if the product is well tolerated and sustained clinical benefit exists.
HS-20093 is a fully humanized IgG1 antibody-drug conjugate (ADC) which specifically binds to B7-H3, a target wildly expressed on solid tumor cells.~This is a phase 2, open-label, multi-center study to evaluate the efficacy, safety, pharmacokinetics (PK) and immunogenicity of HS-20093 as a monotherapy in patients with relapsed or refractory osteosarcoma and other sarcomas.