Sobi and Sanofi announced that the XTEND-Kids phase 3 pivotal study evaluating the safety, efficacy and pharmacokinetics of efanesoctocog alfa as once-weekly prophylaxis in previously treated patients under 12 years of age with severe haemophilia A met its primary endpoint. No factor VIII inhibitors were observed in the 74 children enrolled in the study, of which 65 experienced at least 50 exposure days. Efanesoctocog alFA provided high sustained factor VIII levels throughout the weekly dosing interval with a median annualised bleeding rate (ABR) of 0.00 (interquartile range: 0.00-1.02) and an estimated mean ABR (95% confidence interval) of 0.89 (0.56-1.42).

Haemophilia A is a rare, genetic disorder in which the ability of a person's blood to clot is impaired due to a lack of factor VIII. Haemophilia A occurs in about one in 5,000 male births annually, and more rarely in females. People with haemophilia can experience bleeding episodes that can cause pain, irreversible joint damage and life-threatening haemorrhages.

Despite advancements in treatment made in recent years, a large unmet medical need still exists and requires further improvement in the standard of care. EfanesoctocOG alfa is a new class of factor VIII replacement therapy decoupled of von Willebrand factor, providing high sustained factor activity levels with a once-weekly prophylactic treatment regimen. Combined with the XTEND-1 phase 3 trial, these results will provide the basis for regulatory submission in the EU.

Efanesoctococog alfa was granted orphan designation by the European Commission in June 2019 and the medicine was recently approved in the US.