• HEMGENIX^® is the first and only gene therapy approved by the U.S. Food and Drug Administration (FDA) for the treatment of hemophilia B and to show sustained efficacy and safety at three years post-treatment
• Long-term data continues to show a one-time infusion of HEMGENIX offers elevated and sustained factor IX activity levels for years and significantly reduces the rate of annual bleeds versus factor IX prophylaxis with a favorable safety profile
• At three years post-treatment with HEMGENIX, 94% of patients remained free of continuous prophylactic treatment

Global biotechnology leader CSL  announced the three-year results from the pivotal HOPE-B study confirming continued long-term durability and safety of HEMGENIX^® (etranacogene dezaparvovec-drlb) following a one-time infusion in people living with hemophilia B. The data showing that a one-time infusion of HEMGENIX offers elevated and sustained factor IX activity levels for years were presented in an oral presentation at the 65th American Society of Hematology (ASH) Annual Meeting and Exposition. HEMGENIX is the first and only gene therapy for the treatment of adults with hemophilia B who currently use factor IX prophylaxis therapy, or have current or historical life-threatening bleeding, or have repeated, serious spontaneous bleeding episodes.

"The long-term follow-up data from the HOPE-B study reinforces that a one-time treatment with HEMGENIX can produce elevated and sustained factor IX levels and reduce the rate of annual bleeds for years in people living with hemophilia B," said Dr. Steven Pipe, Professor of Pediatrics and Pathology at the University of Michigan and principal investigator of the HOPE-B pivotal trial. "Most importantly, the data show that nearly all the Phase III trial participants three years post-treatment with HEMGENIX have remained free from the need for regular prophylactic infusions, which is groundbreaking for the hemophilia B community."

The Phase III, open label, single-dose, single arm HOPE-B trial included 54 male participants with severe or moderately severe hemophilia B with or without pre-existing AAV5 neutralizing antibodies. Of the 54 participants who received HEMGENIX, 52 completed three years of follow-up. HEMGENIX produced mean factor IX levels of 41.5 IU/dL at year one, 36.7 IU/dL at year two and 38.6 IU/dL at year three post-treatment. In addition, 94% (51 out of 54) of patients remained free of continuous prophylactic therapy.

The three-year data also demonstrated that the mean annualized bleeding rate (ABR) for all bleeds was reduced by 64% during months 7-36 of the study (mean ABR 1.52 vs. 4.17 during the lead-in period; p=0.0004), sustaining the same bleed reduction that satisfied the study's primary endpoint. The FDA-approved prescribing information for HEMGENIX shows that ABR for all bleeds was reduced by 54% during months 7-18 of the study. Median bleeds per participant decreased from 2.0 during the lead-in period and remained stable at 0.0 during years one to three.

There were no serious adverse events related to treatment with HEMGENIX. HEMGENIX was generally well-tolerated, with most treatment-emergent adverse events (76%) considered mild; 95% of adverse events occurred before 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).

"Gene therapy is a novel treatment that addresses unmet needs in the hemophilia B community and the data presented at ASH continues to provide confidence in the clinical benefits of HEMGENIX," said Steven Pascoe, M.D., Chief Medical Officer, CSL. "As part of our commitment to the hemophilia B community, we will continue to follow the participants from the HOPE-B study as well as those who have been treated with HEMGENIX post FDA approval to generate additional evidence supporting the long-term safety, efficacy and durability of this one-time treatment. We encourage healthcare professionals to continue to have open conversations with their patients about individual treatment goals and whether HEMGENIX may be an appropriate treatment option."

In addition to the presentation of the three-year results of the HOPE-B trial, two posters on HEMGENIX were presented evaluating HEMGENIX in patients with comorbidities. The first (Abstract #2258) assessed HEMGENIX in hemophilia B patients with a history of chronic hepatitis C and hepatitis B infections and the second (Abstract #2256) investigated those with human immunodeficiency virus (HIV). Additionally, an analysis on the indirect treatment comparison of HEMGENIX and factor IX prophylaxis was recently published in Haemophilia.

HEMGENIX also has been granted conditional marketing authorization by the European Commission (EC) for the European Union and European Economic Area, and the United Kingdom's Medicines and Healthcare products Regulatory Agency (MHRA), as well as authorization by Health Canada. The multi-year clinical development of HEMGENIX was led by uniQure (Nasdaq: QURE) and sponsorship of the clinical trials transitioned to CSL after it licensed global rights to commercialize the treatment. Earlier this year, CSL announced the first person living with hemophilia B had received HEMGENIX.