Optimised CD33 (FL-33) CAR T Therapy for Refractory/Relapsed Acute Myeloid Leukaemia

This study is a multi-center, open-label, non-randomised, single-arm phaseⅠclinical trial to explore the safety and efficacy of FL-33 CAR T therapy for refractory/relapsed acute myeloid leukaemia. The primary endpoints are incidence and type of dose limiting toxicity within 21 days of CAR T infusion; total number, incidence and severity of adverse events (AE) 30 days after CAR T infusion. The secondary endpoints are total number, incidence and severity of AEs 30 days to 2 years after CAR T infusion; objective response rate (ORR), complete response rate (CR) and complete response with incomplete haematological recovery (CRi) by dose group at 15, 30 and 90 Days after CAR T Infusion; duration of response (DOR), progression-free survival (PFS), overall survival (OS); pharmacokinetic characteristics. The trial will use BOIN12 design to explore the optimal biological dose (OBD) of FL-33 CAR T cells for refractory/relapsed acute myeloid leukaemia. FL-33 CAR T is set at two dose levels: 5\*10\^5 (±20%) CAR-T cells/kg for dose 1 (DL-1) and 1\*10\^6 (±20%) CAR-T cells/kg for dose 2 (DL-2), and after the optimal biological dose (OBD) is determined in the dose exploration phase, the dose expansion phase will expand the trial by 6-12 cases at the OBD, enrolling up to 21-27 cases. Enrolment of more than 21 cases can be reported for analysis and the trial will be stopped when enrolment reaches 27 cases.Additionally, an independent observation group was established, comprising two sequential cohorts: a minimum of 3 subjects were enrolled starting from the lowest dose level (DL-1).