Based on the favorable activity of topotecan as a single agent, topotecan was also used in combination with cytarabine in high-risk MDS (i.e., RAEB with >10% blasts or RAEBt). A CR rate of 56% was achieved, with a low rate of induction mortality (7%) in a population with a median age of 68 years. These results were at least equivalent to those achieved with an idarubicin and cytarabine combination both in a retrospective comparison of two different trials, and in a prospective randomized trial.