A prospective, multicenter, observational study of long-term decitabine treatment in patients with myelodysplastic syndrome.

This prospective observational study evaluated the efficacy and safety of long-term decitabine treatment in patients with myelodysplastic syndrome (MDS). Decitabine 20 mg/m(2)/day was administered intravenously for 5 consecutive days every 4 weeks to MDS patients in intermediate-1 or higher International Prognostic Scoring System (IPSS) risk categories. Active antimicrobial prophylaxis was given to prevent infectious complications. Overall response rate (ORR), overall survival (OS), progression-free survival (PFS), and time to response were evaluated, as were adverse events. The final analysis included 132 patients. IPSS risk was intermediate-2/high in 34.9% patients. The patients received a median of 5 cycles, with responders receiving a median of 8 cycles (range, 2-30). ORR was 62.9% (complete response [CR], 36; partial response [PR], 3; marrow complete response [mCR], 19; and hematologic improvement, 25). Among responders, 39% showed first response at cycle 3 or later. OS at 2 years was 60.9%, with 17% progressing to acute myeloid leukemia. PFS at 2 years was 51.0%. Patients achieving mCR showed comparable survival outcomes to those with CR/PR. With active antibiotic prophylaxis, febrile neutropenia events occurred in 61 of 1,033 (6%) cycles. Long-term decitabine treatment with antibiotic prophylaxis showed favorable outcomes in MDS patients, and mCR predicted favorable survival outcomes.