The Phase 3 study, XTEND‐1 (NCT04161495), showed once‐weekly efanesoctocog alfa (50 IU/kg) prophylaxis provided mean FVIII activity levels >40 IU/dL for ∼4 days and 15 IU/dL at Day 7 in adults/adolescents with severe haemophilia A [6]. Here, F8 is linked to hemophilia A.