FCGRT and cancer: GLP-grade SPEDOX-6 at 30 mg/kg is significantly better than Doxil at 4 mg/kg (MTD) and DOX at 3.5 mg/kg (MTD) in inhibiting SK-ES-1 (Ewing sarcoma model, with the highest FcRn expression level among cancer cell lines) tumor growth, but SPEDOX-6 has less efficacy against SK-ES-1, relative to HT-1080.