#United States #King of Prussia #HEMGENIX #Hemophilia B #CSL Behring

Sustained Results of HEMGENIX® After Four Years

Introduction

In a significant advancement for hemophilia B treatment, CSL Behring has announced the four-year outcomes of its gene therapy, HEMGENIX® (etranacogene dezaparvovec-drlb). This innovative therapy has demonstrated impressive long-term efficacy and safety, marking a milestone in the management of this hereditary bleeding disorder. The data was presented at the 18th Annual Congress of the European Association for Haemophilia and Allied Disorders (EAHAD) held in early February 2025, showcasing the therapy's impact on adult patients living with hemophilia B.

Key Findings

The latest reports indicated that 94% of the patients who received HEMGENIX could discontinue factor IX prophylaxis entirely and maintained that status over four years. These individuals benefited from significantly improved mean factor IX activity levels, which remained near normal levels at 37% through the observed period. This reinforces the profound efficacy of HEMGENIX in managing hemophilia B.

The pivotal Phase 3 HOPE-B trial established that a single infusion of HEMGENIX provided long-lasting bleed protection. Remarkably, the adjusted annualized bleeding rate (ABR) for all reported bleeds decreased by approximately 90% comparing the bleeding rates from the lead-in period to year four.

Clinical Significance

The implications of these findings are particularly important as hemophilia B can lead to severe complications such as spontaneous bleeds into joints, which cause pain, swelling, and can lead to permanent joint damage. Dr. Steven Pipe of the University of Michigan emphasized the significance of HEMGENIX's ability to alleviate these burdens through effective, long-term treatment that minimizes the need for recurrent prophylactic infusions.

In the study, 54 adult men with varying severity of hemophilia B participated, with 51 completing the four-year follow-up. The mean factor IX levels recorded were 41.5 IU/dL initially, and although there were minor fluctuations in subsequent evaluations (36.7 IU/dL at year two, 38.6 IU/dL at year three, and 37.4 IU/dL at year four), this data emphasizes sustained expression of the therapeutic protein following a single treatment.

The incidence of severe adverse events associated with HEMGENIX usage was negligible, indicating the treatment is generally well-tolerated. A majority of adverse events observed were mild, primarily transient liver enzyme elevations during the first six months post-treatment.

Broader Implications

CSL Behring’s Vice President, Andres Brainsky, has stressed the ongoing commitment to monitor and report additional data about HEMGENIX to ensure healthcare providers and patients have access to critical information for informed decision-making. Approvals for HEMGENIX span various regulatory bodies, including the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA), reflecting a comprehensive and supportive regulatory landscape that encourages innovation in genomic therapies.

Furthermore, CSL Behring's partnership with uniQure, the pioneer behind HEMGENIX, illustrates a successful model of collaboration that emphasizes the real-world implications and potential for expanded clinical use of gene therapies in complex conditions like hemophilia B.

Conclusion

The long-term results of HEMGENIX present a compelling case for its role in changing the treatment paradigm for hemophilia B. By offering profound efficacy and a favorable safety profile, HEMGENIX stands out as a groundbreaking therapy capable of improving the quality of life for individuals affected by this condition. Through continued research and community engagement, CSL Behring is set to enhance therapeutic options available to hemophilia patients everywhere, aiming for a future where treatments can significantly mitigate the challenges of this life-altering disorder. For more information on HEMGENIX, please visit www.Hemgenix.com.