People with the condition lack a working copy of the gene for clotting factor VIII and often infuse it into a vein multiple times a week for life. Researchers tested a one-time gene therapy meant to let the body make its own factor VIII instead.
In the GENEr8-1 trial, led by Margareth Ozelo, a single dose of valoctocogene roxaparvovec was infused into 134 men with severe hemophilia A. Over the following year, factor VIII levels rose, most participants no longer needed routine factor VIII infusions, and treated bleeds fell sharply.
For some patients, years of scheduled infusions gave way to no routine treatment at all after a single procedure. But the therapy's effect faded over time in many patients, as factor VIII production measured in blood tests declined year over year, which delayed regulatory approval while agencies weighed how durable the benefit really was.
Read the original study
One infusion, far fewer bleeds.
Source
- Ozelo, M. C., Mahlangu, J., Pasi, K. J., Giermasz, A., Leavitt, A. D., Laffan, M., Symington, E., Quon, D. V., Wang, J.-D., Peerlinck, K., Pipe, S. W., Madan, B., Key, N. S., Pierce, G. F., O'Mahony, B., Kaczmarek, R., Henshaw, J., Lawal, A., Jayaram, K., . . . GENEr8-1 Trial Group (2022). Valoctocogene Roxaparvovec Gene Therapy for Hemophilia A. New England Journal of Medicine, 386(11), 1013–1025. https://doi.org/10.1056/NEJMoa2113708