Clinical utility of lenalidomide in the treatment of myelodysplastic syndromes

Abstract

Abdallah Abou Zahr,1 Ehab Saad Aldin,2 Rami S Komrokji,3 Amer M Zeidan4 1Section of Hematology/Oncology, Department of Internal Medicine, Mount Sinai Beth Israel, New York City, New York, NY, 2Department of Internal Medicine, Medstar Good Samaritan Hospital, Baltimore, MD, 3Department of Malignant Hematology, H Lee Moffitt Cancer Center and Research Institute, Tampa, FL, 4Division of Hematology, Department of Medicine, Yale University, New Haven, CT, USA Abstract: Myelodysplastic syndromes (MDS) represent a heterogeneous group of acquired clonal hematopoietic disorders characterized by peripheral blood cytopenias, paradoxical BM hypercellularity, ineffective hematopoiesis, and increased risk of leukemic transformation. Risk stratification, using different prognostic scores and markers, is at the core of MDS management. Deletion 5q [del(5q)] MDS is a distinct class of MDS characterized by the haploinsufficiency of specific genes, microRNAs, and proteins, which has been linked to increased sensitivity to the drug lenalidomide. Phase II and III clinical trials have demonstrated the efficacy of lenalidomide in improving clinical outcomes of patients with del(5q) MDS, including reduction in red blood cell transfusion requirements and improvements in quality of life. Lenalidomide has also demonstrated some activity in non-del(5q) lower-risk MDS as well as higher-risk MDS, especially in combination with other agents. In this paper, we review the pathogenesis of del(5q) MDS, the proposed mechanisms of action of lenalidomide, the major clinical trials that documented the activity of lenalidomide in different MDS populations, potential predictors of benefit from the drug and suggested mechanisms of resistance, and the use of combination strategies to expand the clinical utility of lenalidomide in MDS. Keywords: deletion 5q, lenalidomide, myelodysplastic syndromes, 5q-syndrome