A Prospective Single-center Study on the Efficacy and Safety of Lenalidomide Combined With Azacitidine vs Azacitidine in the Treatment of MDS-RS

Myelodysplastic neoplasms (MDS) are heterogeneous clonal disorders of stem cells that result in peripheral blood cytopenia and ineffective hematopoiesis, with the potential risk of the development of acute myeloid leukemia (AML). Most patients with myelodysplastic syndromes with ring sideroblasts (MDS-RS) are stratified into lower-risk groups by the revised International Prognostic Scoring System (IPSS). At present, the main therapies for MDS-RS are red blood cell and platelet transfusion, erythropoietin (EPO), androgen, and iron chelation therapy. Lenalidomide is an immunomodulator with multiple mechanisms, including direct targeting of MDS clones, immunomodulation, erythropoiesis restoration, and angiogenesis inhibition. Hypomethylating agents (HMA) like azacytidine (AZA) and decitabine (DEC), have been shown to improve survival or delay disease progression in high-risk MDS. A Phase III, randomized, placebo-controlled trial of oral AZA in lower-risk MDS reported higher rates of hemoglobin and platelet hematological improvement in patients with AZA monotherapy (24.3% vs 6.5%). Therefore, this study intended to investigate the efficacy and safety of lenalidomide and sequential azacitidine in the treatment of refractory MDS-RS versus azacitidine monotherapy.