uniQure N.V. announced that its partner CSL announced the publication in the New England Journal of Medicine (NEJM) (Vol. 388 No. 8) of results from the pivotal HOPE-B clinical study evaluating the efficacy, durability and safety of HEMGENIX (etranacogene dezaparvovec-drlb).

HEMGENIX is the first and only gene therapy approved 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 multi-year clinical development of HEMGENIX was led by uniQure and sponsorship of the clinical trials transitioned to CSL after it licensed global rights to commercialize the treatment. HEMGENIX was approved in November 2022 by the U.S. Food and Drug Administration (FDA), and in February 2023 by the European Commission (EC) for the European Union.

Results from the HOPE-B trial, the largest gene therapy study in hemophilia B to date, were considered by the authors to demonstrate that HEMGENIX is superior to routine factor IX prophylaxis in Annualized Bleeding Rate (ABR), factor IX activity, factor IX therapy consumption, factor IX infusion rate, and spontaneous and joint bleeding ABR. Increased factor IX activity was also apparent from week 3 and maintained over 18 months. There were no reported serious adverse events related to treatment with HEMGENIX.

Notably, the results published in NEJM show the ABR of spontaneous bleeding episodes and all joint bleeding episodes decreased by 71% (95% CI: 0.12, 0.71) and 78% (95% CI: 0.10, 0.46), respectively, from lead-in period to post-treatment. Further, 96.3% of patients discontinued factor IX prophylaxis from day 21 through month 18 post-treatment. Annualized factor IX infusions also significantly decreased from 72.5 infusions per participant during lead-in period (95% CI: 63.6, 82.7) to 2.5 infusions (95% CI: 0.92, 6.96) post-treatment.

The most common adverse reactions (incidence =5%) were elevated ALT, headache, blood creatine kinase elevations, flu-like symptoms, infusion-related reactions, fatigue, malaise and elevated AST.