Low-dose melphalan for treatment of high-risk myelodysplastic syndromes.

Twenty-one consecutive patients with high-risk myelodysplastic syndromes (MDS) including six with refractory anemia with excess blasts (RAEB) and 15 with RAEB in transformation (RAEBt) were treated with daily oral low-dose melphalan (2 mg/day). Seven patients achieved complete remission (CR), one patient partial response, and four minor response while the remaining eight did not respond. The median age of the patients was 65 (range 56-83 years). The mean total amount of melphalan given was 140+/-19 mg in patients who achieved CR. The median duration of CR was 14.5 months. Serious toxicity was not encountered in any of the cases. Neither marrow suppression nor pancytopenia was observed during the administration of melphalan in patients who achieved CR. The clinical features of CR patients included normal karyotype and hypocellular marrow in biopsied specimen from the lilac bone. These observations suggest that melphalan may exert some differentiation effects on leukemic cells in addition to cytotoxic effects. Our study indicates that daily administration of low-dose melphalan is worth trying in the treatment of elderly patients with high-risk MDS.