Treatment Options for Chronic Myelomonocytic Leukemia (CMML)

Disease Classification and Initial Assessment

The World Health Organization classifies CMML as a clonal hematopoietic malignancy with features of both myelodysplastic syndrome and myeloproliferative neoplasm 3
Initial evaluation should include bone marrow aspiration and biopsy with cytogenetic analysis, peripheral blood evaluation, and molecular testing 4
CMML is categorized into two main phenotypes: Myelodysplastic CMML (MD-CMML) and Myeloproliferative CMML (MP-CMML), with blast percentage in bone marrow being a critical factor for treatment decisions 1, 2
The European Hematology Association recommends considering the disease phenotype and blast percentage when making treatment decisions 1, 2

For Myelodysplastic CMML (MD-CMML) with low blast count, the European Society for Medical Oncology recommends supportive therapy aimed at correcting cytopenias 1, 3, 2
For Myelodysplastic CMML (MD-CMML) with low blast count, erythropoietic stimulating agents are recommended for severe anemia 1, 2
For Myeloproliferative CMML (MP-CMML) with low blast count, cytoreductive therapy with hydroxyurea is recommended to control proliferative myelomonocytic cells and reduce organomegaly 1, 3, 2

The European Society for Medical Oncology recommends allogeneic stem cell transplantation as the only potentially curative option for CMML 1, 2
Reduced intensity conditioning (RIC) transplant has shown improved outcomes compared to myeloablative conditioning 1, 2
For MP-CMML with high blast count, transplant should be preceded by polychemotherapy 1, 2

The European Hematology Association recommends patients not receiving treatment should have full blood count one month after diagnosis, then every three months 5
For patients on treatment, response assessment should follow modified International Working Group response criteria 5
Bone marrow examination should be performed yearly and with any significant hematologic changes 5

The American Society of Hematology recommends avoiding delaying treatment in symptomatic patients or those with high blast counts, and using intensive chemotherapy in elderly patients or those with significant comorbidities 6
Neglecting supportive care alongside disease-modifying therapy should be avoided 6
Failing to recognize disease progression from MD-CMML to MP-CMML, which requires treatment strategy adjustment, should be avoided 5