Decitabine Containing Conditioning Regimen for Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Intermediate- and High-Risk Myelodysplastic Syndrome/Acute Myeloid Leukemia: Potential Decrease in the Incidence of Acute Graft Versus Host Disease

Objective: To evaluate the role of Decitabine in the allo-HSCT conditioning regimen for intermediate- and high-risk patients with MDS or AML.

Methods:Retrospective analysis of data pertaining to 76 intermediate and high-risk patients with MDS or AML who underwent allo-HSCT between December 2005 and June 2018 at the Peking University First Hospital. Forty patients received Decitabine containing conditioning regimen before transplantation, while thirty-six patients received regimen without Decitabine.

Results: Overa median follow up of 40 months(range, 1 to 155), the incidence of grade II to IV acute graft versus host disease was 12.5% in the Decitabine group and 41.7% in the non-Decitabine group (P=0.003). On multivariate analysis, Decitabine containing conditioning regimen was found to protect against grade II to IV aGVHD (HR=0.275, 95% confidence interval 0.098-0.770,P=0.014). Incidence of respiratory infection in the Decitabine and non Decitabine groups was 22.5% and 52.78%, respectively (P=0.012). No significant between group difference was observed with respect to 3-year OS, DFS, or RR (P=0.980, 0.959, and 0.837, respectively), while the median relapse time was longer in the Decitabine group [7 months (range, 2 to 12) versus 3 months (range, 2 to 4), P=0.171]. Decitabine containing conditioning showed a tendency for lower relapse rate among higher risk patients, as assessed by IPSS R; however, the between-group difference was not statistically significant (P=0.085).

Conclusions: Inclusionof Decitabine in the conditioning regimen for allo-HSCT in intermediate- and high-risk patients may lower the incidence of aGVHD and respiratory infections, and contribute to longer median relapse time.