In 132 adult males with haemophilia A, the GENEr8-1 study showed that valoctocogene roxaparvovec increased FVIII activity from baseline (when participants were receiving FVIII prophylaxis) to Month 24 post-treatment by a mean of 22.0 IU/dL and 35.1 IU/dL using chromogenic and one-stage assays, respectively [6]. Here, F8 is linked to hemophilia A.