BioMarin's ROCTAVIAN Gene Therapy Shows Sustained Efficacy After Five Years in Severe Hemophilia A
Key Insights
BioMarin's Phase 3 GENEr8-1 trial demonstrates that ROCTAVIAN gene therapy maintains durable bleed control and sustained factor VIII (search) expression five years after treatment in severe hemophilia A patients.
The study shows 81.3% of participants remain off prophylaxis after five years, with mean factor VIII (search) activity in the mild hemophilia range and no new safety signals observed.
Results from the longest and largest hemophilia gene therapy study reveal significant quality of life improvements across multiple measures, including reduced bleeding risk and enhanced physical activity.
BioMarin Pharmaceutical Inc. has presented compelling five-year data from its Phase 3 GENEr8-1 trial, demonstrating the sustained long-term efficacy and safety of ROCTAVIAN (valoctocogene roxaparvovec-rvox) gene therapy for severe hemophilia A. The results, presented at the 33rd Congress of the International Society on Thrombosis and Haemostasis (ISTH) in Washington, D.C., represent data from the longest and largest hemophilia gene therapy study to date.
Sustained Factor VIII Expression and Bleed Control
The trial demonstrated that durable bleed control and sustained factor VIII (search) (FVIII (search)) expression were maintained five years after treatment with ROCTAVIAN. Among the 134 individuals who received the gene therapy, the rollover population of 112 patients from the 270-902 noninterventional lead-in study showed remarkable durability of treatment effects.
After five years, FVIII (search) activity remained nearly stable compared to year four, with mean FVIII activity in the mild hemophilia range (one-stage assay = 24.0 IU/dL; chromogenic assay = 13.7 IU/dL). Notably, 73.5% of participants achieved FVIII levels in the mild hemophilia to normal range. The mean annualized bleeding rate (ABR) for treated bleeds in the rollover population was 0.6 bleeds per year after five years.
"I am impressed that the strong efficacy and safety results for ROCTAVIAN are sustained five years after individuals with severe hemophilia A received gene therapy, with only one adult returning to prophylaxis since the last data cut," said Andrew Leavitt, M.D., director of the University of California San Francisco's program for noncancerous blood disorders and Adult Hemophilia Treatment Center.
Prophylaxis Independence and Bleeding Control
The study revealed that 81.3% (n=109) of participants remained off prophylaxis at the end of year five. During year five specifically, 77.8% of the remaining participants (n=108) in the rollover population experienced zero treated bleeds, demonstrating the therapy's ability to provide sustained protection against bleeding episodes.
Safety Profile Remains Favorable
ROCTAVIAN continued to demonstrate a favorable safety profile with no new safety signals observed over the five-year period. Across the entire trial, no participants developed FVIII (search) inhibitors or experienced thromboembolic events, and there were no treatment-related malignancies reported throughout the study duration.
Quality of Life Improvements
Additional data presented at the meeting described a framework for measuring the "hemophilia-free mind" in patients who received ROCTAVIAN, representing an easing of the physical and psychological burden of hemophilia. Researchers used clinical data and questionnaires to assess quality of life outcomes from baseline to week 104.
The analysis showed that people who received ROCTAVIAN in the Phase 3 GENEr8-1 study experienced improvements across all measures, including bleeding risk, joint pain, injection schedule, physical activity, travel, employment and education, and impact on family members and caregivers.
"We hope these results demonstrating the long-term durability of gene therapy equip individuals with severe hemophilia A with the knowledge to make informed decisions regarding treatment," said Dawn Rotellini, Chief Operating Officer at the National Bleeding Disorders Foundation.
Clinical Significance and Future Implications
The five-year data reinforce ROCTAVIAN's potential to transform the treatment landscape for severe hemophilia A. ROCTAVIAN is an adeno-associated virus vector-based gene therapy that works by delivering a functional gene designed to enable the body to produce FVIII (search) on its own, reducing the need for ongoing prophylaxis.
"These five-year data reinforce our confidence in ROCTAVIAN's profile, showing that people living with severe hemophilia A can experience long-term bleed control without the need for prophylaxis, meaningfully impacting the mental and clinical burdens of this condition," said Greg Friberg, M.D., Executive Vice President and Chief Research & Development Officer at BioMarin.
The therapy received conditional marketing authorization from the European Commission on August 24, 2022, and FDA approval on June 29, 2023. Hemophilia A affects approximately 1 in 10,000 people and is an X-linked genetic condition caused by missing or defective FVIII (search), a clotting protein essential for blood coagulation.