Sanofi/Sobi’s Hemophilia A Therapy Highly Effective in Children

Sanofi and Sobi have announced that their once-weekly haemophilia A treatment has shown impressive results in children with severe cases of the disorder, according to phase 3 research published in The New England Journal of Medicine.

Haemophilia A is a genetic condition that affects about one in every 5,000 male births each year. It is caused by an insufficient amount of functioning factor VIII, a protein vital for blood clotting. Efanesoctocog alfa, a factor VIII replacement therapy administered intravenously, has been approved for both adults and children with haemophilia A. This therapy is marketed under the name Altuviiio in the US, Japan, and Taiwan by Sanofi. Recently, Sobi received marketing authorization from the European Commission to use the therapy in patients of all ages under the brand name Altuvoct.

The phase 3 XTEND-Kids study assessed a once-weekly dosage of efanesoctocog alfa over 52 weeks in children under 12 years old who had been previously treated for severe haemophilia A. The trial achieved its primary and secondary objectives, which included the incidence of factor VIII inhibitors and annualized bleed rates (ABRs). The findings revealed that no inhibitors to factor VIII developed among the participants, with a median ABR of zero and an estimated mean ABR of 0.61 in the study involving 73 patients treated according to the protocol.

Moreover, 82% of the children experienced no joint bleeds while using efanesoctocog alfa. The therapy was well tolerated, with no adverse events prompting the discontinuation of treatment. Dietmar Berger, global head of development and chief medical officer at Sanofi, expressed that the data confirms the link between sustained high factor activity levels and better health outcomes, particularly concerning joint health.

Echoing this, Lydia Abad-Franch, head of research, development, and medical affairs, and chief medical officer at Sobi, stated that the XTEND-Kids study further highlights the safety and efficacy of efanesoctocog alfa. She emphasized that maintaining high factor VIII activity can lead to improved clinical outcomes in children.

Sanofi and Sobi are jointly involved in the development and commercialization of efanesoctocog alfa in the US. In Europe, North Africa, Russia, and most Middle Eastern markets, Sobi holds the final development and commercial rights, while Sanofi retains these rights in North America and other regions worldwide outside the Sobi territory.