Valoctocogene roxaparvovec, a gene therapy for severe Hemophilia A (HA), helps prevent bleeding by providing the body with genetic instructions for making factor VIII (FVIII) protein. We report findings from the GENEr8-1 study 4-years after participants received valoctocogene roxaparvovec. To compare health-related quality-of-life (HRQOL) outcomes before and after treatment with valoctocogene roxaparvovec.

In GENEr8-1 (NCT03370913), 134 adult men with severe HA received one infusion of valoctocogene roxaparvovec (6E13 copies of FVIII instructions/kg). To assess their HRQOL, participants completed questionnaires before receiving valoctocogene roxaparvovec and regularly afterwards. The Haemo-QOL-A, a questionnaire designed for HA and B, is being validated for gene therapy for HA. It produces a Total Score reflecting overall HRQOL and domain scores measuring impacts on specific aspects of life, such as Physical Functioning (eg, ability to carry out everyday tasks), Role Functioning (eg, relationships and ability to function in social roles), and Consequences of Bleeding (fear of having a bleed/what happens after you have a bleed). Here, Haemo-QOL-A results are presented for the 132 HIV-negative participants in total and by the participants'FVIII activity level at year 4. Other questionnaires will be included in the final presentation.

Four years after treatment with valoctocogene roxaparvovec, the average Haemo-QOL-A Total Score increased by 6.2-points, an average improvement considered meaningful to people with severe HA. Improvements were also seen for Physical Functioning (4.8-points), Role Functioning (5.9-points), and Consequences of Bleeding (9.2-points). At year 4, average Haemo-QOL-A Total Score increased by 6.3, 5.8, and 6.9 points for year 4 FVIII activity in ranges ≥ 40%, ≥ 5% to < 40%, and < 5%, respectively.

Valoctocogene roxaparvovec provides HRQOL improvements considered meaningful for people with severe HA over 4-years, even for participants with FVIII levels below 5% at year 4.