Allogeneic stem cell transplantation for patients harboring T315I BCR-ABL mutated leukemias

T315I⁺ Philadelphia chromosome-positive leukemias are inherently resistant to all licensed tyrosine kinase inhibitors, and therapeutic options remain limited.We report the outcome of allogeneic stem cell transplantation in 64 patients with documented BCR-ABL^T315I mutations. Median follow-up was 52 months from mutation detection and 26 months from transplantation. At transplantation, 51.5% of patients with chronic myeloid leukemia were in the chronic phase and 4.5% were in advanced phases. Median overall survival after transplantation was 10.3 months (range 5.7 months to not reached [ie, still alive]) for those with chronic myeloid leukemia in the blast phase and 7.4 months (range 1.4 months to not reached [ie, still alive]) for those with Philadelphia chromosome-positive acute lymphoblastic leukemia but has not yet been reached for those in the chronic and accelerated phases of chronic myeloid leukemia. The occurrence of chronic GVHD had a positive impact on overall survival (P ∇ .047). Transplant-related mortality rates were low. Multivariate analysis identified only blast phase at transplantation (hazard ratio 3.68, P ∇ .0011) and unrelated stem cell donor (hazard ratio 2.98, P ∇ .011) as unfavorable factors. We conclude that allogeneic stem cell transplantation represents a valuable therapeutic tool for eligible patients with BCR-ABL^T315I mutation, a tool that may or may not be replaced by third-generation tyrosine kinase inhibitors.