Enhanced Survival of Chronic Myelomonocytic Leukemia (CMML)-Dysplastic over Proliferative Subtype After Allogeneic Hematopoietic Cell Transplant: A Tertiary Center Experience and Literature Review.

Abstract

INTRODUCTION CMML is a rare neoplasm with overlapping myelodysplastic and myeloproliferative features whose only potential cure is allogeneic hematopoietic cell transplantation (allo-HCT). METHODS This retrospective study examined 27 CMML patients with high-risk clinical features who underwent first allo-HCT at our institution between 2004 and 2022. RESULTS 19 patients were diagnosed with the proliferative subtype (CMML-MPN), and 8 with the dysplastic subtype (CMML-MDS). Median OS was 15 months post-HCT (95% CI: 5-71); OS at 1, 3, and 5 years was 52%, 35%, and 35%, respectively. Compared to those with CMML-MPN, patients with CMML-MDS had longer OS (median, 8.6 vs 0.9 years; P=0.025), RFS (4.4 vs 0.5 years; P=0.021), and GVHD-free, relapse-free survival (GRFS, 9.4 vs 3.4 months; P=0.033) as well as lower 1-year NRM (13% vs 47%; P=0.043), with the statistical significance of this CMML subtype effect maintained in multivariable models. High-risk cytogenetics were associated with shorter GRFS in the univariable (median, 3.1 vs 6.2 months; P=0.013) and multivariable (HR=4.88; P=0.006) settings. CONCLUSIONS Patients who underwent transplant for CMML-MDS experienced substantially better outcomes than those transplanted for CMML-MPN. Future studies are needed for transplantation optimization in CMML, especially CMML-MPN.