A prospective multicenter observational study of decitabine treatment in Korean patients with myelodysplastic syndrome

BACKGROUND: Decitabine was evaluated for its efficacy and safety in Korean patients with myelodysplastic syndrome with IPSS score of 0.5 or over. DESIGN AND METHODS: Decitabine 20 mg/m(2)/day was given intravenously over one hour for five consecutive days every four weeks. The primary end point was overall response rate. RESULTS: A total of 101 patients were analyzed. The International Prognostic Scoring System risk category was Intermediate-2/High in 47.5%. A median of 5 courses (range 1-18) were delivered. The overall response rate was 55.4% (13 complete responses, one partial response, 23 marrow complete responses, and 19 hematologic improvements). Forty-eight patients (47.5%) showed some hematologic improvement. With a median follow-up duration of 478 days (range 69-595), median overall survival was 17.7 months. Patients who showed hematologic improvement had significantly longer overall survival than those who did not (19.2 vs. 15.9 months, P=0.006 by landmark analysis at six months). The difference in overall survival was evident in the Intermediate-2/High risk group but not in the Intermediate-1 risk group. The progression-free survival and acute myeloid leukemia-free survival were 61.9% and 77.9% at one year, respectively. Among 489 assessable treatment courses, there were 97 fever episodes requiring intravenous antimicrobials. CONCLUSIONS: Decitabine treatment was feasible and effective in Korean patients with myelodysplastic syndrome, and the overall survival was significantly longer in patients showing hematologic improvement.ope