Platzbecker U et al. - In the current study, luspatercept was shown to be well-tolerated and effective in the treatment of anaemia in lower-risk myelodysplastic syndromes.

Methods
Eligible patients were 18 years of age or older, had International Prognostic Scoring System-defined low or intermediate risk myelodysplastic syndromes or non-proliferative chronic myelomonocytic leukaemia, and had anaemia with or without red blood cell transfusion support.
Enrolled patients were classified as having low transfusion burden, defined as requiring less than 4 red blood cell units in the 8 weeks before treatment, or high transfusion burden, defined as requiring 4 or more red blood cell units in the 8 weeks before treatment.
Patients received luspatercept subcutaneously once every 21 days at dose concentrations ranging from 0.125 mg/kg to 1.75 mg/kg bodyweight for 5 doses.
Patients in the expansion cohort were treated with 1.0 mg/kg luspatercept; dose titration up to 1.75 mg/kg was allowed, and patients could be treated with luspatercept for a maximum of 5 years.
The primary endpoint was the proportion of patients achieving modified International Working Group-defined haematological improvement–erythroid (HI-E), defined as a haemoglobin concentration increase of 1.5 g/dL or higher from baseline for 14 days or longer in low transfusion burden patients, and a reduction in red blood cell transfusion of 4 or more red blood cell units or a 50% or higher reduction in red blood cell units over 8 weeks versus pre-treatment transfusion burden in high transfusion burden patients.

Results
58 patients with myelodysplastic syndromes were enrolled; 27 patients were enrolled in the dose-escalation cohorts (0.125–1.75 mg/kg) and 31 patients in the expansion cohort (1.0–1.75 mg/kg).
32 of 51 patients receiving higher dose luspatercept concentrations achieved HI-E versus 2 of 9 receiving lower dose concentrations.
Three treatment-related grade 3 adverse events occurred in one patient each.