Refractory anemia with excess of blasts: increased survival when treated with cyclophosphamide, methotrexate and 6-mercaptopurine.

Owing to the lack of efficacious treatments for refractory anemia with an excess of blasts (RAEB), evaluation of other therapeutic strategies is necessary, especially in elderly patients. We report herein our experience with an oral triple drug regimen with cyclophosphamide 200 mg/m2 and methotrexate 20 mg/m2 once a week, and 6-mercaptopurine 50 mg/m2 daily for the treatment of RAEB. Eighteen patients with a median age of 62 yr (range 17-80) received a triple drug regimen (TDR), and they were compared with 6 patients who received oxymetholone (2 mg/m2/d) and 9 who received supportive therapy only. Partial response was achieved in 45% of patients receiving TDR. In 77% of patients treated with TDR the number of bone marrow blasts decreased to <5%; however, they persisted with trilineage dyspoietic morphologic changes. Median survival for TDR was 23 months (range 1-96), which was longer than that for the other groups. A slight rise in liver enzymes was the only side effect of TDR. TDR seems to be a useful alternative in patients with RAEB, a finding to be confirmed in further prospective studies.