[Analysis of the impact of decitabine treatment cycles on efficacy and safety in patients of myelodysplastic syndrome-refractory anemia with excess blasts].

Objective: To explore the impact of decitabine treatment cycles on efficacy and adverse events(AEs)in patients of myelodysplastic syndrome-refractory anemia with excess blasts(MDSRAEB).
Methods: A total of fifty-six patients with MDS-RAEB who received decitabine 20 mg·m-2·d-1by IV infusion daily for 5 consecutive days every 4 weeks at a single institute in China were enrolled from December 2008 to March 2016. Their clinical features, efficacy, predictors of efficacy and AEs were analyzed retrospectively.
Results: Of the 56 patients enrolled, 25 cases were MDS- RAEB1, another 31 were MDS-RAEB2. A median of 3 cycles(range, 1-15 cycles)were delivered. The overall response rate was 67.9%(10 complete responses, 8 marrow complete responses without hematologic improvement, 17 marrow complete responses with hematologic improvements, and 3 hematologic improvements). With a median follow-up duration of 7.9(1.0-56.3)months, the median overall survival was 21.1(95% CI 16.0- 26.1)months. Compared with RAEB-2, RAEB-1 predicted higher overall response rates in a multivariate analysis. Of the 38 patients who experienced clinical responses, initial responses were detected by the end of two cycles in 37 patients. Twenty- five of the 38 patients who experienced clinical responses had their best response within the first two cycles, and 37 cases of the patients achieved best response by the end of fourth cycles. Grade 3 or 4 cytopenia and infection were the most prevalent AEs, which occurred frequently in the early courses and decreased later, and other non- hematologic AEs were rare.
Conclusion: Decitabine treatment was favorable in patients with MDS- RAEB. In most of the cases, initial responses were observed within 2 cycles, and best response was achieved by the end of 4 th cycles. The most common AEs were grade 3 or 4 cytopenia and infection, which were observed frequently in first 2 cycles and decreased later as objective response were achieved.