A 7-Day Decitabine-Included Conditioning Regimen Accelerated Donor Hematopoietic Engraftment while Reduced the Occurrence of Mucositis without Interfering with Prognosis

Introduction: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the standard and curative treatment strategy for patients with hematologic malignancies. Recently, decitabine-included regimens have been investigated by several studies including ours, which may prevent relapse of primary malignant diseases. Methods: This study was to retrospectively evaluate a 7-day decitabine-included regimen with reduced dose of idarubicin for patients with hematologic malignancies who underwent allo-HSCT. Results: A total of 84 patients were enrolled, including 24 cases in 7-day and 60 cases in 5-day decitabine groups, respectively. Patients conditioned with 7-day decitabine regimen showed accelerated neutrophil (12.05 ± 1.97 vs. 13.86 ± 3.15; u = 9.309, p < 0.001) and platelet (16.32 ± 6.27 vs. 21.37 ± 8.57; u = 8.887, p < 0.001) engraftment compared with those treated with 5-day decitabine regimen. Patients in the 7-day decitabine group showed a significantly lower incidence rate of total (50.00% [12/24] versus 78.33% [47/60]; χ² = 6.583, p = 0.010) and grade III or above (4.17% [1/24] vs. 31.67% [19/60]; χ² = 7.147, p = 0.008) oral mucositis compared to those in the 5-day decitabine group. However, the occurrence of other major complications post-allo-HSCT and outcomes of patients in these two groups were comparable. Conclusion: These results demonstrate that this 7-day decitabine-contained new conditioning regimen seems to be feasible and safe for patients with myeloid neoplasms who receive allo-HSCT, and a large-scale prospective study is needed to confirm the findings of this study.