The effect of pretransplant interferon therapy on the outcome of unrelateddonor hematopoietic stem cell transplantation for patients with chronic myelogenous leukemia in first chronic phase

Various therapeutic options are available for patients with chronic myeloge nous leukemia. Allogeneic stem cell transplantation, though often curative, is associated with high nonrelapse mortality and long-term morbidity, part icularly when cells from unrelated donors are used. Many physicians and pat ients opt for a trial of interferon-alpha (IFN)-based therapy first, reserv ing transplantation for patients with inadequate response or intolerance to IFN. Data were analyzed on 740 patients receiving unrelated donor transpla nts for chronic myelogenous leukemia in first chronic phase provided by the International Bone Marrow Transplant Registry and the National Marrow Dono r Program to see whether IFN pretreatment compromised transplantation outco me. A total of 489 (66%) had received IFN prior to transplantation; 251 (34 %) had not. Disease characteristics in the 2 groups were similar at diagnos is but at the time of transplantation, hematologic parameters and weight we re lower in IFN patients and the interval between diagnosis and transplanta tion was longer. After adjustment for baseline covariates, no effect of IFN exposure was found on overall survival, leukemia-free survival, nonrelapse , mortality, engraftment, relapse, or acute or chronic graft-versus-host di sease. Evaluation of effects based on duration of therapy and time off IFN prior to transplantation was limited by missing data and confounding with I FN intolerance and disease responsiveness. In conclusion, no evidence was f ound for an independent adverse effect of IFN pretreatment on the outcome o f subsequent unrelated donor transplantation. (Blood. 2001;98:3205-3211) (C ) 2001 by The American Society of Hematology.