Study of HS-20093 Versus Gemcitabine in Combination With Docetaxel in Treatment of Osteosarcoma After Previous Second-line Treatment Failure

Study participants in the experimental group shall continue to receive HS-20093 by intravenous infusion at a dose of 12.0 mg/kg, once every 3 weeks (Q3W) with a 21-day treatment cycle. Treatment shall continue until objective disease progression (excluding cases of treatment beyond PD or crossover treatment) or until other criteria for termination of study treatment specified in the protocol are met.

Study participants in the control arm will receive gemcitabine in combination with docetaxel. Gemcitabine (1000 mg/m2) will be administered intravenously over approximately 30 minutes on Days 1 and 8 of each 21-day treatment cycle, followed by docetaxel (75 mg/m2) on Day 8, intravenously over approximately 1 hour until objective disease progression or other criteria for treatment discontinuation are met.