Treatment Sequence of Lenalidomide (LEN) and Hypomethylating Agents (hmas) and the Impact on Clinical Outcomes for Patients with Myelodysplastic Syndromes (MDS)

Introduction: MDS comprise a heterogeneous group of hematological malignancies with 10,000-20,000 cases diagnosed in the US annually. Although erythropoiesis-stimulating agents are often used in lower-risk (LR) MDS, 3 agents are approved for the treatment of MDS in the US: HMAs (azacitidine and decitabine) and LEN. Given the limited response rates and ultimate treatment failure with these drugs, they are used in sequence. Despite being available for over a decade, there are little data on the impact of their sequencing on clinical outcomes. One small single-center study by Zeidan et al (2015) in 63 patients with non-del(5q) LR-MDS concluded that LEN is optimally positioned before azacitidine when the drugs are in sequence. The current study aimed to look at this question using a real-world MDS patient dataset not restricted to non-del(5q) LR-MDS patients who were treated with an HMA followed by LEN (HMA-LEN) or LEN followed by an HMA (LEN-HMA).