Biopharmaceutical company Swedish Orphan Biovitrum AB (Sobi) (STO:SOBI) reported on Tuesday that the first patient has been dosed in the phase 3, open-label, interventional XTEND-Kids study of efanesoctocog alfa (BIVV001) in children with severe haemophilia A.

Efanesoctocog alfa is being developed and will be commercialised in partnership with Sanofi (EPA:SAN).

In the non-randomised, single-arm study, participants will receive a weekly prophylactic dose of efanesoctocog alfa for 52 weeks. The trial will evaluate efficacy, safety and pharmacokinetics in approximately 65 previously treated patients aged 12 years and under.

Efanesoctocog alfa was granted Fast Track designation by the US Food and Drug Administration (FDA) in February 2021. It was also granted Orphan Drug designation by the US FDA in August 2017 and the European Commission in June 2019.