Conditioning therapy with N‐acetyl‐L‐cysteine, decitabine and modified BUCY regimen for myeloid malignancies patients prior to allogeneic hematopoietic stem cell transplantation

Abstract Conditioning therapy is an essential procedure prior to hematopoietic stem cell transplant (HSCT), imposing a great impact on the outcomes of recipients. We performed a prospective randomized controlled trial to assess the outcome of HSCT recipients with myeloid malignancies after receiving the conditioning therapy consisting of modified BUCY (mBUCY), N‐acetyl‐L‐cysteine (NAC), and decitabine. Enrolled patients were randomly allocated to either Arm A (decitabine, day −12 to −10; NAC, day −9 to +30; mBUCY, day −9 to −2), or Arm B (mBUCY regimen followed by stem cells infusion). Seventy‐six patients in Arm A and 78 patients in Arm B were finally evaluated. The results showed platelet recovery accelerate in Arm A, with more patients achieving a platelet count of ≥50 × 10 9 /L than Arm B at day +30 and +60 ( p = .004 and .043, respectively). The cumulative incidence of relapse is 11.8% (95% CI 0.06–0.22) in Arm A, and 24.4% (95% CI 0.16–0.35) in Arm B ( p = .048). The estimated 3‐year overall survival rate was 86.4% (±4.4%) and 79.9% (±4.7%) in 2 arms, respectively ( p = .155). EFS at 3 years was 79.2% (±4.9%) in Arm A and 60.0% (±5.9%) in Arm B ( p = .007). Intracellular reactive oxygen species (ROS) level was found to be reversely correlated with platelet recovery, and fewer patients in Arm A displayed excessive ROS within hematopoietic progenitor cells compared to Arm B. In conclusion, the addition of decitabine and NAC to mBUCY is a feasible and promising conditioning therapy for myeloid malignancies patients.