Allogeneic stem cell transplantation for chronic myelomonocytic leukemia : a report from the Société Française de Greffe de Moelle et de Thérapie Cellulaire

Objectives and methods: Chronic myelomonocytic leukemia (CMML) is a severe disease for which
allogeneic stem cell transplantation (allo-SCT) remains the only potentially curative treatment. We describe a retrospective study determining prognostic factors for outcome after allo-SCT in consecutive 73 patients with CMML reported to the SFGM-TC registry between 1992 and 2009. Results: At diagnosis, median age was 53 yrs, and 36% patients had palpable splenomegaly (SPM). 48, 13, and 9 patients had good, intermediate, and poor risk karyotype, respectively, according to IPSS, 61% patients had CMML-1, and 39% had CMML-2. 41/31/1 cases had an HLA-identical sibling, an unrelated and haploidentical donor, respectively. 43 patients received reduced-intensity conditioning. With a median follow-up of 23 month, acute grade 2–4 and chronic GVHD developed in 21 and 25 patients, respectively. The 3-year OS, NRM (non-relapse mortality),EFS, and CIR (cumulative incidence of relapse) were 32%, 36%, 29% and 35%, respectively. OS was not influenced by the CR status, marrow blasts% at allo-SCT, prior treatments, and cGVHD. Using multivariate analysis, year of transplant < 2004 (YOT) (P = 0.005) was associated with higher NRM, YOT < 2004 (P = 0.04) and SPM at allo-SCT (P = 0.02) with lower EFS, and YOT < 2004
(P = 0.03) and SPM at allo-SCT (P = 0.04) with poorer OS. Conclusions: Allogeneic stem cell transplantation is a valid treatment option for patients with CMML, and its outcome has improved with YOT > 2004. Splenomegaly seems to be a negative factor of OS and EFS in this series.