Weeks 25–48 of the extension phase
EVENTS
Of the 68 patients who were initial luspatercept nonresponders (by HI-E) at week 25 and continued treatment, 11 patients (16%) achieved RBC-TI for ≥ 8 weeks during weeks 25–48 of the extension phase. Of these, 3 patients were RBC-TI for ≥ 16 weeks (Online Resource During weeks 25–48, 18 (26%) of the 68 initial luspatercept nonresponders had a reduced RBC transfusion burden relative to baseline. In this group, the mean change (standard deviation (SD)) from baseline in the RBC units transfused was − 3.1 units (6.51) during the first 24 weeks of treatment, rising to − 6.5 units (6.31) during weeks 25–48. In initial luspatercept nonresponders with a full 48 weeks of available treatment data (As a descriptive analysis, the mean change from baseline in hemoglobin levels from weeks 25 to 48 for initial luspatercept nonresponders is shown in Fig. Mean change from baseline in hemoglobin levels, weeks 25–48, in initial luspatercept nonresponders. Number of patients varies as not every patient underwent hemoglobin assessment each weekRBC transfusion events for the 68 initial luspatercept nonresponders during the 16 weeks prior to and 48 weeks after the start of luspatercept treatment are shown in Fig. RBC transfusion events in initial luspatercept nonresponders pre- and post-initiation of luspatercept treatment. Periods of response are denoted by blue lines. 