The Outcome of Sibling and Unrelated Donor Allogeneic Stem Cell Transplantation in Adult Patients with Acute Myeloid Leukemia in First Remission Who Were Initially Refractory to First Induction Chemotherapy

The optimal management of patients with initially refractory acute myeloid leukemia is unknown. We analyzed the outcomes of 68 adult patients (median age, 37 years) with acute myeloid leukemia in first complete remission with initially refractory disease who were treated with matched sibling (n = 44) or unrelated donor (n = 22) stem cell transplantation or who received transplants from other donors (n = 2). Thirty-one patients took 2 courses of chemotherapy to achieve first complete remission, a further 31 took 3 courses, and 6 patients took 4 or 5 courses. Ten patients (15%) had adverse cytogenetics. Patients were mainly conditioned with cyclophosphamide and total body irradiation (87%). Four patients (6%) did not engraft by day 28; 2 of these engrafted at 47 and 60 days. Grades II to IV and III/IV acute graft-versus-host disease (GVHD) were seen in 34% and 14% of patients, respectively. Chronic GVHD was seen in 50% of patients. The estimated actuarial disease-free and overall survivals were 34% and 37%, respectively, at 4 years. The performance status of survivors is good; 82% of patients have Karnofsky scores of 90 to 100. On multivariate analysis, overall and disease-free survival were associated with adverse cytogenetics (P = .055 and .023). Approximately one third of patients survived 4 years after allogeneic stem cell transplantation for initially refractory acute myeloid leukemia in first complete remission: relapse and treatment-related mortality were the major causes of treatment failure. Further studies are needed to determine the optimal conditioning regimens and GVHD prophylaxis.