PROGNOSTIC FACTORS FOR OUTCOMES IN ALLOGENEIC TRANSPLANTATION FOR ADVANCED PHASES OF CHRONIC MYELOID LEUKEMIA IN THE IMATINIB ERA: A CIBMTR ANALYSIS

Allogeneic hematopoietic stem cell transplantation (HSCT) is curative treatment, albeit in a minority of patients with accelerated (AP) or blast phase (BP) chronic myeloid leukemia (CML). Imatinib (IM) has transient but significant activity in advanced phases of CML, which may permit early allografting for responding patients. To identify prognostic factors in allograft recipients previously treated with IM, we analyzed 449 allogeneic HSCT performed between 1999–2004 in advanced phase CML using data reported to the Center for International Blood and Marrow Transplant Research. CML patients in second chronic phase (CP2, n=184), AP (n=185), and BP (n=80) received HLA-identical sibling (27%), related (3%), or matched or mismatched unrelated donor (70%), peripheral blood (47%) or bone marrow (53%) HSCT after myeloablative (78%) or non-myeloablative (22%) conditioning. 52% in CP2, 49% in AP, and 46% in BP received IM pre-HSCT. Disease-free survival was 35–40% for CP2, 26–27% for AP and 8–11% for BP. Cumulative incidence of acute and chronic GVHD and TRM were not affected by stages of CML or pre-HSCT IM exposure. Multivariate analyses showed that conventional prognostic indicators remain the strongest determinants of transplant outcomes. In conclusion, there are no new prognostic indicators of outcomes of allogeneic HSCT for advanced phase CML in the IM era.