Imatinib combined with myeloablative allogeneic hematopoietic stem cell transplantation for advanced phases of chronic myeloid leukemia

To evaluat the efficacy and safety of myeloablative allogeneic hematopoietic stem cell transplantation (allo-HSCT) combined with imatinib for advanced chronic myeloid leukemia (CML), 15 patients with accelerated phase (n = 6) or blast crisis (n = 9) were enrolled in this study. All the patients were conditioned with cyclophosphamide and busulfan, and treated with cyclosporin (CsA)/methotrexate (MTX)/mycophenolate mofetil (MMF) for graft-versus-host disease (GVHD) prophylaxis. Eleven of these 15 patients (73.3%) achieved complete hematologic response to pre-transplant imatinib, and six (40%) achieved a cytogenetic response. No engraftment failure was observed and the early transplant-related mortality was only 6.7%. Grade 3/4 acute GVHD occurred in 13.3% of patients. Chronic GVHD was observed in 61.5%, including 23.1% suffered from extensive disease. The 5-year estimated rates of relapse, transplant-related mortality and overall survival were 21.0 ± 10.8% 13.7 ± 10.8% and 66.0 ± 12.4%, respectively. Ten (66.7%) of 15 patients are alive with complete molecular remission, even after a median follow-up of 25 months after withdrawal of imatinib. In conclusion, even CML in advanced phases may have a satisfactory outcome after myeloablative allo-HSCT combined with imatinib, which may provide good remission prior to transplantation and reduce relapse risk, with low toxicity.