Valoctocogene roxaparvovec is in development for the treatment of adult with severe haemophilia A. Haemophilia A is a rare bleeding disorder, whereby the blood does not clot properly due to the lack of or dysfunction of factor VIII clotting protein. In severe haemophilia A, this causes frequent spontaneous bleeding, including in muscles and joints. The inability of their blood to clot means that patients are at high risk of internal bleeding, including from the brain, increasing their mortality risk.
Valoctocogene roxaparvovec is a gene therapy; it can modify the genes (functional units of heredity) of individuals with haemophilia A so that they can produce the clotting protein needed to allow the blood to clot. If licensed, valoctocogene roxaparvovec would be the first gene therapy for severe haemophilia A. Valoctocogene roxaparvovec administered as a single treatment would be sufficient to maintain normal levels of factor VIII in adult males with severe haemophilia A, and might reduce the need for regular factor VIII prophylaxis (preventative treatment).