Sanofi’s investigational haemophilia therapy has shown significant improvements in bleed protection across all types of the disorder, according to two phase 3 studies recently published in The Lancet and The Lancet Haematology.
Haemophilia A and B are lifelong bleeding disorders in which the body’s blood clotting ability is impaired, leading to excessive and spontaneous bleeding into joints that can result in joint damage and chronic pain.
Sanofi’s fitusiran is designed to lower antithrombin, a protein that inhibits blood clotting, with the goal of promoting thrombin generation to rebalance haemostasis and prevent bleeds.
Across both studies, treatment with once-monthly fitusiran (80mg) reduced annualised bleeding rates by 90% over the comparator groups, showing a statistically significant and clinically meaningful improvement in bleeding episodes when compared to on-demand treatments.
In ATLAS-INH, published in The Lancet, 66% of patients with inhibitors receiving fitusiran experienced zero bleeding episodes compared to 5% receiving an on-demand bypassing agent after nine months of treatment.
Similar results were seen in ATLAS A/B, published in The Lancet Haematology, in which 51% of patients without inhibitors who received fitusiran experienced zero bleeds compared to 5% receiving on-demand clotting factor concentrates.
Sanofi said it is currently investigating the efficacy and safety of fitusiran under a revised regimen which includes lower doses and less frequent dosing.
Dietmar Berger, head of global R&D ad interim and chief medical officer at Sanofi, said: “We are entering a new era in haemophilia where, for the first time, people can choose therapies that meet their personal needs.
“This published data validates our science and adds to a growing body of evidence supporting fitusiran’s potential to transform the treatment landscape. We look forward to sharing additional data on fitusiran later this year.”
The publication comes just over a month after Sanofi and partner Sobi’s once-weekly haemophilia A treatment, Altuviiio, was approved in the US for the prevention and on-demand treatment to control bleeding episodes, as well as for surgery management for adults and children with the disease.
The decision, which marked the first regulatory approval of Altuviiio, was based on results from the phase 3 XTEND-1 study in which the therapy demonstrated superiority to prior factor prophylaxis treatment.