Sanofi and Sobi’s once-weekly haemophilia A treatment has demonstrated “highly effective bleed protection” in children with severe cases of the rare bleeding disorder, according to phase 3 results recently published in The New England Journal of Medicine.
Affecting approximately one in every 5,000 male births annually, haemophilia A is a genetic condition resulting from insufficient levels of functioning factor VIII, a protein that is essential for blood clotting.
Efanesoctocog alfa, a factor VIII replacement therapy given as an intravenous injection, is already approved for adults and children with haemophilia A and marketed as Altuviiio by Sanofi in the US, Japan and Taiwan.
Sobi also received marketing authorisation from the European Commission last month for the use of the therapy, under the brand name Altuvoct, in haemophilia A patients of all ages.
The phase 3 XTEND-Kids study evaluated a once-weekly dose of efanesoctocog alfa for 52 weeks in previously treated severe haemophilia A patients aged under 12 years.
The trial met its primary and secondary endpoints, which included the occurrence of factor VIII inhibitors and annualised bleed rates (ABRs).
The results showed that no inhibitor development to factor VIII was detected with the therapy and demonstrated a median ABR of zero as well as an estimated mean ABR of 0.61 in the study of 73 patients treated per protocol.
Additionally, 82% of patients had zero joint bleeds with efanesoctocog alfa and the therapy was found to be well tolerated, with no adverse events that led to treatment discontinuation.
Dietmar Berger, global head of development and chief medical officer at Sanofi, said the data “validates the connection between high-sustained factor activity levels and improved health outcomes, including joint health”.
Sharing a similar sentiment, Lydia Abad-Franch, head of research, development, and medical affairs, and chief medical officer at Sobi, said: “The recent XTEND-Kids study further underscores the safety and effectiveness of [efanesoctocog alfa], showcasing how high-sustained factor VIII activity can improve clinical outcomes in children.”
Sanofi and Sobi collaborate on the development and commercialisation of efanesoctocog alfa in the US, while Sobi has final development and commercialisation rights in Europe, North Africa, Russia and most Middle Eastern markets, with Sanofi holding these rights in North America and all other regions worldwide, excluding the Sobi territory.