Genetically Engineered Cells (FH-FOLR1 ST CAR T Cells) for the Treatment of Advanced Refractory or Recurrent/Progressive Osteosarcoma, FIERCe Trial

OUTLINE: This is a dose-escalation study of FH-FOLR1 ST CAR T cells. Patients undergo leukapheresis for manufacturing of the FH-FOLR1 ST CAR T cell product on study. Patients receive lymphodepleting therapy with fludarabine intravenously (IV) on days -5 to -2 and cyclophosphamide IV on days -3 to -2. Patients receive FH-FOLR1 ST CAR T cells IV on day 0, 1 or 2 in the absence of unacceptable toxicity. Patients also undergo blood sample collection, and computed tomography (CT), magnetic resonance imaging (MRI) or positron emission tomography (PET) throughout the study. Additionally, patients have the option to undergo tumor biopsy on study. Patients will be monitored closely for at least 28 days after receiving CAR T cells. After completion of study treatment, patients are followed up at days 1, 7, 14, 21, 28, and 42, months 2, 3, 6, 12, and 24, then every 6 months for 3 years followed by annually for 10 years. Patients with ongoing FH-FOLR1 ST CAR T cell persistence are also followed up in months 4, 5, 7, 8, 9, 10, 11, 15, and 18.