Background: Erythropoiesis-stimulating agents (ESAs) are used as first-line (1L) treatment (tx) for the management of symptomatic anemia in LR-MDS. Luspatercept is approved for pts with LR-MDS with ring sideroblasts (RS) who experience ESA failure and are transfusion dependent. We assessed clinical outcomes of pts with LR-MDS with RS, or MDS/myeloproliferative neoplasms with RS and thrombocytosis, treated with luspatercept in US community practices. Methods: This retrospective, observational cohort study used physician-abstracted chart data from community oncology clinics and included adults diagnosed with LR-MDS (including Very low- to Intermediate-risk IPSS-R status) on/after Jan 1, 2015 who received luspatercept for ≥ 3 months (mos) with ≥ 3 mos of follow-up. Transfusion burden (TB) was defined by number of sessions (ses) received in the 8 weeks (wks) prior to luspatercept tx (baseline) and the lowest number for any consecutive period ≥ 8 wks during wks 1–24 of tx: transfusion independent (TI); low TB (LTB), 1–3 ses; and moderate TB (MTB), 4–5 ses. Results: Of 253 pts, 219 (87%) had 1 tx prior to luspatercept tx and 31 (12%) received ≥ 2. ESAs were used as 1L tx in 210 pts (83%). Median follow-up was 5.7 mos. The most common reason for discontinuing initial MDS tx among patients who received ≥ 1 tx prior to luspatercept was lack of anemia improvement (133/250). At baseline, 21 (8%) pts were TI, 208 (82%) had LTB, and 24 (10%) MTB. Median duration of luspatercept tx was 10.8 mos. During wks 1–24, 20/21 (95%) pts remained TI and 201/232 (87%) pts with LTB/MTB at baseline achieved TI for ≥ 8 wks. The Table shows changes in median hemoglobin (Hb), absolute neutrophil count (ANC), and platelet (plt) count. Conclusions: Most pts with LR-MDS received 1L ESAs and over half discontinued the first tx prior to luspatercept due to lack of anemia improvement, highlighting the need for alternative options to improve clinical outcomes. Consistent with data from the MEDALIST trial, 87% of pts with LTB/MTB who received luspatercept achieved TI for ≥ 8 wks, supporting its clinical benefit in routine clinical practice.

C, cycle; cycle every 3 wks p25–p75, 25^th–75^th percentile. ^a Results available for a range of 78–196 pts. ^b A range of 76–170 pts.^c A range of 77–193 pts across C1–8.