CAR19/22 T 细胞鸡尾酒疗法用于异基因造血干细胞移植后复发的 B-ALL

B cell acute lymphocytic leukemia (B-ALL) patients who have relapsed after hematopoietic stem cell transplantation (HSCT) have a poor prognosis, and there is currently no standard approach available. Chimeric antigen receptor (CAR)-T cells induce high rates of initial response and long-term remission among patients with B-cell malignancies, especially B-ALL. Meanwhile, sequential infusion of CAR19/22 T cells has been proven to be effective at preventing tumor immune escape. In the present study, we retrospectively analyzed 23 B-ALL patients who relapsed after allogeneic (allo)-HSCT and underwent sequential infusion of CAR19/22 T cells, including nine donor-derived and 14 recipient-derived, in our center from July 2016 to July 2020, to evaluate the safety and efficacy of the cocktail of two single-specific CAR-T cells in B-ALL patients relapsed after transplantation.

Except for one patient refusing evaluation, the remaining 22 patients achieved minimal residual disease (MRD)-negative complete remission within 30 days after CAR-T infusion. Most toxicities were slight and reversible. The estimated 12-month progression-free survival (PFS) rate was 59. 2% (95% confidence interval [CI], 35. 9% to 76. 5%), and the estimated 12-month overall survival (OS) rate was 67. 4% (95% CI, 43. 2% to 83. 1%). Only two patients had CD19-negative recurrence.

In addition, early recurrence after transplantation, graft-versus-host disease (GVHD) and severe infection after CAR-T infusion were poor prognostic factors.

Our results indicate that sequential infusion of CAR19/22 T cells is safe and effective for relapsed ALL patients after HSCT. This trial was registered at www. chictr. org. cn as #ChiCTR-OPN-16008526.