Phase II study of low-dose topotecan in myelodysplastic syndromes: a Hoosier Oncology Group (HOG) study.

Topotecan has demonstrable activity in high-risk MDS and CMMoL. However, the significant toxicity of topotecan administered at a dose of 2mg/m2 i.v. daily for 5 days as a continuous infusion limits its use in older patients. Therefore, we studied topotecan 1.5mg/m2 per day i.v. over 2 h for three consecutive days in 20 patients with high-risk MDS (12 RAEB; 4 RAEB-T; 4 CMMoL). Cycles were given every 4-6 weeks. Fifteen patients were evaluable for response. Only one patient achieved a durable complete remission (CR). There were three deaths within the first cycle of therapy. Severe myelosuppression was the most common toxicity. Grades 3-4 infections were documented in four patients. We conclude that topotecan administered at this dose and schedule has no clinically significant activity.