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

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 /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.