Phase II trial of 2-chlorodeoxyadenosine in patients with relapsed/refractory acute myeloid leukemia: A study of the Eastern Cooperative Oncology Group (ECOG), E5995

2-Chlorodeoxyadenosine (2-CdA) is a purine analog which has anti-leukemic activity in phase II trials in pediatric acute myeloid leukemia (AML) patients. An adult phase I trial suggested possible similar activity although neurotoxicity at higher doses was seen. We conducted a phase II trial of 2-CdA in patients with relapsed or refractory AML. 2-CdA was administered by continuous intravenous infusion at a dose of 17 mg/m² per day x5 days. Patients not achieving aplasia by day 21 were eligible for a second course of therapy. Fifteen patients (nine relapsed and six refractory AML) were enrolled including seven men and eight women with a median age of 60 years and median ECOG PS of 1. There were five deaths on study due to infections (two), AML (two), or hepatic failure (one). The 2-CdA was well tolerated without severe nausea, vomiting or stomatitis (all <grade 2). No severe neurologic complications related to 2-CdA were seen. Grade 4 myelosuppression occurred in nearly all patients with prolonged periods of pancytopenia and BM hypoplasia seen in most. There were no complete responses, though bone marrow aplasia was achieved in eight patients. 2-CdA as a single agent, in the doses used in this study, is ineffective therapy for relapsed or refractory AML. (C) 2000 Elsevier Science Ltd.