Decitabine: in myelodysplastic syndromes

Decitabine is a hypomethylating agent. Its action in DNA leads to the reactivation of tumour suppressor genes and the subsequent differentiation of cancer cells. In a randomised, phase III trial in patients (n = 170) with myelodysplastic syndromes (MDS), intravenous decitabine (45 mg/m(2)/day for 3 consecutive days every 6 weeks) combined with supportive care achieved a higher response rate (including eight complete and seven partial responses) than supportive care alone, which achieved no responses (17% vs 0%; p < 0.001). The median times to response and duration of response were 3.3 and 10.3 months in the phase III trial. In three phase II studies in patients (n = 29-87) with MDS treated with decitabine (40 or 50 mg/m(2)/day for 3 days every 5-6 weeks), the percentage of patients achieving a complete or partial response or an improvement ranged from 26% to 49%, and the median duration of response or improvement ranged from 4.9 to 8.3 months. The main adverse event associated with decitabine is myelosuppression.