Abstract:

Objective To observe the clinical efficacy and safety of luspatercept in managing refractory anemia among patients with myelodysplastic syndrome with ring sideroblast (MDS-RS). Methods A retrospective analysis was performed on consecutive MDS-RS patients with refractory anemia who were treated with luspatercept at Department of Hematology, Shanghai Sixth People’s Hospital, Shanghai Jiao Tong University School of Medicine between August 2022 and December 2023. Eligible patients met the 2016 WHO diagnostic criteria for MDS-RS and were in the very low-, low-, or intermediate- risk groups according to the revised International Prognostic Scoring System (IPSS-R). Luspatercept was administered per label instructions, and a consistent transfusion strategy was required for each patient before and during treatment. Hematologic data and red blood cell transfusion episodes were recorded for each treatment cycle, and hematologic improvement (HI) was assessed using the revised International Working Group (IWG) 2018 criteria. Results 9 patients were enrolled. 7 patients achieved HI, among whom 5 achieved HI-erythroid (HI-E) and 2 achieved red blood cell transfusion independence (TI-RBC) for ≥8 weeks. The median duration of HI response was 17 (9−46) weeks. 5 of the 7 responding patients experienced loss of response, with a median time to first loss of 15 (9−23) weeks. During the study, impacted by the COVID-19 pandemic, 5 patients experienced 6 infection episodes. Treatment delays occurred 11 times in 6 patients, and all delays led to a decrease in hemoglobin [mean decrease, (18±6) g/L] or the need for red blood cell transfusions, directly resulting in 5 dose escalation and loss of response in 2 cases. 3 patients reported bone pain. 1 patient showed progression to grade 3 marrow fibrosis. 33.3% (3/9) reported bone pain, and 1 case showed progression to grade 3 marrow fibrosis. Conclusions This study confirms the real-world efficacy of luspatercept in patients with MDS-RS and refractory anemia. However, its efficacy is influenced by baseline transfusion burden and treatment delays, and depended on continuous and regular administration.

Key words: Myelodysplastic syndrome with ring sideroblast, Luspatercept, Transfusion dependence