VP-16-213 was studied in 38 adult patients with relapsed or refractory acute myeloid leukemia as part of a randomized trial in an ECOG master protocol. In this group of heavily pretreated patients, an overall response rate of 18% was achieved (5% CR, 13% PR). Toxicity was mild, and aplasia was rarely observed. Responses were seen in all of the FAB myeloid subtypes. Patients who had never achieved remission status responded as well as patients who had relapsed.