Luspatercept cuts blood transfusion burden in β-thalassaemia
Luspatercept significantly reduces the need for blood transfusion in patients with β-thalassaemia, thus providing a new hope for patients with β-thalassaemia in whom no approved definitive curative treatments have been available yet other than bone marrow transplantation, according to the BELIEVE* study presented at ASH 2018.
“There is an unmet need for new treatment options in β-thalassaemia patients,” said Dr Maria Domenica Cappellini of Fondazione IRCCS Ca’ Granda Policlinico Hospital at University of Milan, Italy. “[The] currently available management for β-thalassaemia is limited to transfusions and iron chelation therapy, and … patients may require frequent and lifelong transfusions.”
Luspatercept, a first-in-class erythroid maturation agent, enhances late-stage erythropoiesis by binding to certain TGF-β superfamily ligands to block aberrant Smad2/3 signalling.
In the phase III, double-blind, multinational BELIEVE trial, significantly more patients treated in with luspatercept achieved the primary endpoint of ≥33 percent reduction from baseline** in red blood cell (RBC) transfusion burden during weeks 13–24 compared with those on placebo (21.4 percent vs 4.5 percent; odds ratio, 5.79; p<0.0001). [ASH 2018, abstract 163]
Similarly for the key secondary endpoint at 37–48 weeks, significantly more patients in the luspatercept arm had ≥33 percent reduced need for RBC transfusions compared with the placebo arm (19.6 percent vs 3.6 percent; p<0.0001).
A ≥50 percent reduction in transfusion burden also occurred in significantly more patients in the luspatercept arm vs the placebo arm at weeks 13–24 (7.6 percent vs 1.8 percent; p=0.0303) and weeks 37–48 (10.3 percent vs 0.9 percent; p=0.0017).
“Luspatercept achieved a reduction in transfusion burden across any 12- and 24-week analyses compared to placebo,” said Cappellini, who noted that ≥33 percent reduction in RBC transfusions over any consecutive 12 weeks was achieved in significantly more patients in the luspatercept arm than the placebo arm.
The study involved 336 patients (median age 30 years, 58 percent female) with β-thalassaemia or haemoglobin E/β thalassaemia who needed regular blood transfusions of 6–20 RBC units within the 24 weeks period before randomization, during which transfusion-free period of ≥35 days was not allowed. They were randomized in a 2:1 ratio to receive either subcutaneous administration of luspatercept*** or placebo every 3 weeks for 48 weeks, after which, the patients were unblinded and allowed to cross-over to the other arm and were followed up post-treatment up to 3 years. In both arms, patients continued treatment with iron chelation therapy and RBC transfusions to maintain their baseline haemoglobin level.
“Luspatercept was generally well tolerated in this patient population,” said Cappellini. “Adverse events [AEs] observed in the study were generally consistent with previously reported phase II data … [being] generally mild to moderate, and manageable without requiring dose modifications or interruptions.”
There were also no deaths reported in the luspatercept arm.
“Luspatercept is a potential new therapy option for adult patients with β-thalassaemia who require regular RBC transfusions,” she concluded.