Steven W. Pipe, MD, on the End-of-Study Results From Hemgenix’s HOPE-B Trial

“At the 6 month point after dosing, the mean FIX activity was in the near normal range, at 39%, and now, 5 years later, this whole cohort is still sitting at about 36% for their FIX expression. And if we look across the cohort, this looks to be very stable amongst the individual participants. This is really encouraging that we really have been able to deliver durable FIX expression over the long term.”

CSL Behring/uniQure’s etranacogene dezaparvovec (marketed as Hemgenix), a gene therapy product for the treatment of severe or moderately severe hemophilia B with or without preexisting AAV5 neutralizing antibodies (NAbs), was approved by the FDA in November 2022.¹ The therapy is intended to provide durable factor IX (FIX) expression, bleed protection, and freedom from prophylaxis.

The FDA’s decision to approve Hemgenix, which was the first hemophilia B gene therapy to be approved by the agency, was based partly on results from the pivotal phase 3 HOPE-B clinical trial (NCT03569891). Although, long-term follow-up of the study’s participants remained ongoing until early 2025.

Finally, at the 67th American Society of Hematology (ASH) Annual Meeting and Exposition, held December 6 to 9, 2025, in Orlando, Florida, end-of-study data from HOPE-B were presented by Steven W. Pipe, MD, a professor of pediatric hematology/oncology at the University of Michigan Health, who served as the trial’s principal investigator.² CGTLive® sat down with Pipe at the conference to learn more about the updated findings. Pipe went over the key efficacy and safety data, noting that of 54 participants, only 2 did not respond to the treatment. The remaining patients showed stable FIX activity, averaging 36% at 5 years after treatment with Hemgenix. Furthermore, annualized bleeding rates fell sharply, dropping from about 4 per year at baseline to 1.5 per year across follow up. Pipe also noted that safety was favorable, with the vast majority of treatment-related adverse events occurring in the first 6 months.

For more coverage of ASH 2025, click here.

REFERENCES
1. FDA approves first gene therapy to treat adults with hemophilia B. News release. FDA. November 22, 2022. https://www.fda.gov/news-events/press-announcements/fda-approves-first-gene-therapy-treat-adults-hemophilia-b
2. Pipe S, Miesbach W, Recht M, et al. End-of-study analysis of the HOPE-B trial confirms the durable efficacy and safety of etranacogene dezaparvovec hemophilia b gene therapy over 5 years. Presented at: ASH 2025 Annual Meeting. December 6-9, 2025; Orlando, FL. Abstract #538