One-time infusion of Hemgenix offers long-term durability, phase 3 HOPE-B trial shows
February 8, 2025Global biotechnology company CSL Behring announced on Friday the four-year results from the pivotal HOPE-B study confirming the long-term durability and safety of a one-time infusion of HEMGENIX for adults living with haemophilia B.
The data showed that through four years, HEMGENIX® continues to deliver elevated and sustained factor IX activity levels, can offer long-term and greater bleed protection compared to prophylactic treatment, can eliminate the need for routine factor IX prophylaxis, and maintains a favourable safety profile, the company said.
Receiving conditional marketing authorisation from the European Medicines Agency (EMA) in 2023, HEMGENIX® is the first gene therapy approved for the treatment of severe and moderately severe haemophilia B (congenital factor IX deficiency) in adult patients without a history of factor IX inhibitors, the company said. It is also the only approved gene therapy for haemophilia B that can treat adult patients with and without AAV5 neutralising antibodies thereby providing the potential for a greater number of eligible patients to be treated, the company said.
According to Behring, in the Phase III, open-label, single-dose, single-arm HOPE-B trial, 54 adult male participants with severe or moderately severe haemophilia B, with or without preexisting AAV5 neutralising antibodies, were infused with a single dose of HEMGENIX®. Of the 54 participants who received HEMGENIX®, 51 completed four years of follow-up. HEMGENIX® produced mean factor IX levels of 41.5 IU/dL (n=50) at year one, 36.7 IU/dL (n=50) at year two, 38.6 IU/dL (n=48) at year three and 37.4 IU/dL (n=47) at year four post-infusion. In addition, mean adjusted annualised bleeding rate (ABR) for all bleeds was reduced by approximately 90% from lead-in (4.16, n=54) as compared to year four (0.40, n=51). Furthermore, joint bleeds were reduced from a mean ABR of 2.34 at lead-in to 0.09 during year four. In year four, 94% of patients remained free of continuous prophylaxis treatment. No patients returned to continuous prophylaxis between year three and year four, the company said.
There were no serious adverse events related to treatment with HEMGENIX®. HEMGENIX® was generally well-tolerated, with a total of 96 treatment-related adverse events (AEs), 92 (96%) of which occurred in the first six months post-treatment. The most common adverse events were an increase in alanine transaminase (ALT), for which nine (16.7%) participants received supportive care with reactive corticosteroids for a mean duration of 81.4 days (standard deviation: 28.6; range: 51-130 days).
“These data continue to instill confidence in the clinical benefits of HEMGENIX®, highlighting the remarkable impact of this one-time treatment to reduce the frequency of bleeds in people with haemophilia B and improve quality of life by alleviating the burden of ongoing factor IX prophylactic treatment,” said Andres Brainsky, Vice President R&D Hematology at CSL. “CSL is committed to continuing to provide ongoing data analyses of HEMGENIX®, ensuring that healthcare providers and patients have the necessary information to make informed decisions about treatment options. We are proud to continue to provide life-changing treatment options to the haemophilia community.”