Outcome of allogeneic SCT in patients with chronic myeloid leukemia in the era of tyrosine kinase inhibitor therapy

The introduction of tyrosine kinase inhibitors (TKIs) for chronic myeloid leukemia (CML) led to a dramatic change in the role of allogeneic stem cell transplantation (SCT) with a rapid decline in the number of patients receiving SCT in first chronic phase (CP1). We evaluated 68 consecutive patients in all phases of CML (male/female = 39:29, 27 in CP1), who received SCT from related/unrelated donors (related/unrelated = 23:45) under myeloablative or reduced intensity conditioning (MAC/RIC = 45:23). Forty-eight patients (71 %) received TKIs pre-SCT, 20 patients post-SCT (29 %). Overall survival (OS) of CP1 patients achieved a plateau of 85 % at 10 months. Relapse-free survival (RFS) of CP1 patients was 85 % at 1 and 2 years, and 81 % at 5 years. Multivariate analysis showed adverse OS and RFS for patients transplanted > CP1 (hazard ratio (HR) = 6.61 and 4.62) and those who had grade III-IV aGvHD (HR = 2.45 and 1.82). Patients with advanced CML had estimated OS of 65 and 47 %; and RFS of 41 and 32 % at 1 and 2 years respectively. Therefore, for patients with advanced CML phases, allogeneic SCT provides an acceptable chance of cure. Transplant research should focus on improving conditioning regimens and post-SCT management for this subgroup of CML patients.