IM83 Clinical Study of CAR-T Cell Therapy in Patients With Relapsed or Refractory Osteosarcoma

IM83 CAR-T Cells, 5×10\^8 cells, 1×10\^9 cells, and 2×10\^9 cells, treatment follows a lymphodepletion. Drug: Fludarabine Recommendation: 30 mg/m\^2 (D-5\~D- 3), determined by tumor burden at baseline. Drug: Fludarabine Recommendation: 30 mg/m\^2 (D-5\~D-3), determined by tumor burden at baseline. Drug: Cyclophosphamide Recommendation: 300 mg/ m\^2 (D-5\~D-3), determined by tumor burden at baseline.