Evaluation of temozolomide in patients with myelodysplastic syndrome

In our previous phase I study of temozolomide in patients with acute leukemia, temozolomide was well tolerated and demonstrated significant anti-leukemic activity. The maximum tolerated dose was 200 mg/m2/d for 7 days, repeated approximately every 5-6 weeks. In the current study, we evaluated the same dose of temozolomide in patients with myelodysplastic syndrome. Fourteen patients received 19 courses of temozolomide. The median age was 71 years. In this study, treatment was poorly tolerated with patients requiring admission in 9 of 19 courses. Toxicity included worsening cytopenias, neutropenic fever, and exacerbation of cardiac disease, the latter due to worsening anemia. An unusual finding was the development of leukocytoclastic vasculitis in 4 patients. There were no formal responses to therapy. The current schedule of temozolomide is not efficacious in patients with myelodysplastic syndrome.