Comparison of Intensive Chemotherapy and Hypomethylating Agents before Allogeneic Stem Cell Transplantation for Advanced Myelodysplastic Syndromes: A Study of the Myelodysplastic Syndrome Subcommittee of the Chronic Malignancies Working Party of the Europ

• Before hematopoietic stem cell transplantation, the use of hypomethylating agents or conventional chemotherapy as pretransplantation therapy result in similar outcomes
• These results are observed despite the older age and lower numbers of patients achieving complete remission in the hypomethylating agent group
• Patients with primary refractory disease do not do well with either approach and newer strategies to optimize outcome in this group are required

The European Society for Blood and Marrow Transplant Research data set was used to retrospectively analyze the outcomes of hypomethylating therapy (HMA) compared with those of conventional chemotherapy (CC) before hematopoietic stem cell transplantation (HSCT) in 209 patients with advanced myelodysplastic syndromes. Median follow-up was 22.1 months and the median age of the group was 57.6 years with 37% of the population older than > 60 years. The majority of patients (59%) received reduced-intensity conditioning and 34% and 27% had intermediate-2 and high international prognostic scoring system (IPSS) scores. At time of HSCT, 32% of patients did not achieve complete remission (CR) and 13% had primary refractory disease. On univariate analysis, outcomes at 3 years were not significantly different between HMA and CC for overall survival (OS), relapse-free survival (RFS), cumulative incidence of relapse (CIR), and nonrelapse mortality (NRM): OS (42% versus 35%), RFS (29% versus 31%), CIR (45% versus 40%), and NRM (26% versus 28%). Comparing characteristics of the groups, there were more patients < 55 years old, more patients in CR (68% versus 32%), and fewer patients with primary refractory disease in the CC group than in the HMA group (10% versus 19%, P < .001). Patients with primary refractory disease had worse outcomes than those in CR with regard to OS (hazard ratio [HR], 2.42; 95% confidence interval [CI], 1.41 to 4.13; P = .001), RFS (HR, 2.27; 95% CI, 1.37 to 3.76; P = .001), and NRM (HR, 2.49; 95% CI, 1.18 to 5.26; P = .016). In addition, an adverse effect of IPSS-R cytogenetic risk group was evident for RFS. In summary, outcomes after HSCT are similar for patients receiving HMA compared with those receiving CC, despite the higher proportion of patients with primary refractory disease in the HMA group.