Chronic myelomonocytic leukemia: molecular pathogenesis and therapeutic innovations.

Chronic myelomonocytic leukemia (CMML) is an aggressive clonal stem cell disorder categorized amongst myelodysplastic/myeloproliferative (MDS/MPN) overlap neoplasms. While sharing features with both MDS and MPN, CMML has distinct molecular and clinical profiles. The presence of CMML-specific prognostic models, response criteria, and dedicated clinical trials underscores a unique and complex biology. Agerelated changes affecting the bone marrow microenvironment, immune responses, and the intricate balance between epigenetic deregulation and proinflammatory signaling are characteristic of this disease, collectively posing significant scientific and clinical challenges in management. CMML is an ageing-related, clinically heterogeneous neoplasm with limited approved therapeutic options, representing an area of unmet medical need. This review offers a comprehensive analysis of the current understanding of the molecular mechanisms driving CMML evolution and its clinical manifestations within the ever-evolving landscape of precision medicine. In light of the most recent molecular discoveries, we highlight the pitfalls of existing therapies and underscore promising investigational agents. Many of the biological findings discussed are shared across a spectrum of acute and chronic myeloid neoplasms, as well as clonal hematopoiesis, broadening the scope of this review.