First Gene Therapy for Haemophilia B, HEMGENIX® Approved by the European Commission

On February 20, 2023, the European Commission has granted conditional marketing authorisation (CMA) for HEMGENIX® (etranacogene dezaparvovec-drlb)

The Haemophilia community is celebrating strides in treatment availability following recent approval of HEMGENIX® (etranacogene dezaparvovec-drlb), the first and only one-time gene therapy for the treatment of severe and moderately severe Haemophilia B (congenital Factor IX deficiency) in adults without a history of Factor IX inhibitors.

HEMGENIX® is a single dose intravenous infusion that reduces the rate of abnormal bleeding by enabling the body to continuously produce Factor IX (FIX), a protein needed to form blood clots and stop bleeding. Specifically, HEMGENIX® utilizes a viral vector to deliver the genetic instructions for making Factor IX to target cells in the liver. Once delivered, the new genetic instructions remain in the target cells and generate factor IX proteins that are five to eight times more active than normal. It is the first approved gene therapy for Haemophilia B in the European Union (EU) and European Economic Area (EEA) and provides a one-time treatment alternative to the routine FIX injections.

Haemophilia B is a lifelong bleeding disorder caused by a single gene defect that reduces the production of a protein called clotting Factor IX (FIX). Although the disease is most often passed down from parents to children, about one-third of cases are caused by a spontaneous mutation or change in a gene. All races and ethnic groups are affected but men are the most likely to have symptoms. The severity of Haemophilia B varies depending on the level of FIX produced by the patient. In milder cases, prolonged or heavy bleeding may only occur after an injury, surgery, or dental procedure. In severe cases, bleeding episodes can occur spontaneously without a clear cause. Patients may also experience prolonged bleeding in joints, muscles, and internal organs, which leads to pain, swelling, and joint damage. Frequent prophylactic FIX infusions can reduce joint bleeding events, prevent life-threatening bleeds, and help to preserve joint functions. Unfortunately, even with prophylactic therapy, unobservable, yet harmful micro-bleeds can still occur.

People living with Haemophilia B currently require lifelong treatment of intravenous infusions of Factor IX to maintain sufficient levels, which can have a significant impact on their quality of life and wellbeing.² According to the European Medicines Agency's (EMA) Committee for Medicinal Products for Human Use (CHMP), there is 'an unmet medical need for new therapeutic approaches that might free patients from the burden of frequent infusions, or episodically at the time of a bleeding event'.³

The European Commission's decision follows the CHMP's positive opinion in December 2022, based on findings from the pivotal HOPE-B trial, the largest gene therapy trial in Haemophilia B to date.⁴ ⁵ These findings showed that Haemophilia B patients treated with HEMGENIX® demonstrated stable and durable increases in mean Factor IX activity levels (with a mean Factor IX activity of 36.9%) which led to an adjusted annualized bleed rate (ABR) reduction of 64%.¹ Following infusion of HEMGENIX®, 96% of patients discontinued routine Factor IX prophylaxis and mean Factor IX consumption was reduced by 97% at 18 months post-treatment, compared to the lead-in period.¹

The European Commission has the authority to approve medicines for EU Member States, as well as well as in the EEA countries of Iceland, Norway and Liechtenstein.

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. In the United Kingdom, The Medicines and Healthcare products Regulatory Agency (MHRA) is currently reviewing CSL's submission for HEMGENIX®. HEMGENIX® was approved by the U.S. Food and Drug Administration in November 2022.

To learn more about Haemophilia B and HEMGENIX®, click here.