In a phase II study (CALGB 100103/Alliance/Blood and Marrow Transplant Clinical Trial Network 0502) reported in the Journal of Clinical Oncology,1 Steven M. Devine, MD, of The Ohio State University, Columbus, et al found that reduced-intensity conditioning allogeneic hematopoietic stem cell transplantation produced favorable survival outcomes and was fairly well tolerated in older patients with acute myeloid leukemia (AML) in first complete remission.
In the study, 114 patients aged 60 to 74 years undergoing hematopoietic stem cell transplantation received a conditioning regimen consisting of fludarabine at 30 mg/m2 intravenously (IV) over 30 minutes for 5 days on days –7 to –3 and busulfan at 0.8 mg/kg over 2 hours every 6 hours for 8 doses on days –4 and –3. The primary endpoint was disease-free survival at 2 years after hematopoietic stem cell transplantation.
At 2 years, disease-free survival was 42% (95% confidence interval [CI] = 33%–52%), and overall survival was 48% (95% CI = 39%–58%) among all patients and 40% (95% CI = 29%–55%) and 50% (95% CI = 38%–64%) among patients with unrelated donors. The cumulative incidence of relapse at 2 years was 44% (95% CI = 35%–53%). Nonrelapse mortality at 2 years was 15% (95% CI = 8%–21%). Grade 2 to 4 acute graft-vs-host disease occurred in 9.6% (grade 3 or 4 in 2.6%), and chronic graft-vs-host disease occurred in 28%.
The investigators concluded: “Reduced-intensity conditioning hematopoietic stem cell transplantation to maintain remission in selected older patients with AML is relatively well tolerated and appears to provide superior outcomes when compared with historical patients treated without hematopoietic stem cell transplantation. Graft-vs-host disease and nonrelapse mortality rates were lower than expected. Future transplantation studies in these patients should focus on further reducing the risk of relapse.” ■
Disclosure: The study was supported by grants from the NCI, the NHLBI, and Genzyme. For full disclosures of the study authors, visit www.jco.ascopubs.org.