Posted: 24 November
Global biotechnology leader CSL announced that the U.S. Food and Drug Administration (FDA) approved HEMGENIX® (etranacogene dezaparvovec-drlb), the first and only one-time gene therapy for appropriate adults with hemophilia B. HEMGENIX is approved for the treatment of adults with hemophilia B who currently use factor IX prophylaxis therapy, or have current or historical life-threatening hemorrhage or have repeated, serious spontaneous bleeding episodes. In the ongoing clinical trial, HEMGENIX reduced the rate of annual bleeds and 94 percent of patients discontinued factor IX prophylaxis and remained prophylaxis-free.
Hemophilia B is a rare, lifelong bleeding disorder caused by a single gene defect, resulting in insufficient production of factor IX, a protein primarily produced by the liver that helps blood clots form. Treatments for moderate to severe hemophilia B include prophylactic infusions of factor IX replacement therapy to temporarily replace or supplement low levels of blood-clotting factor and, while these therapies are effective, those with hemophilia B must adhere to strict, lifelong infusion schedules. They may also still experience spontaneous bleeding episodes as well as limited mobility, joint damage or severe pain as a result of the disease. For appropriate patients, HEMGENIX allows people living with hemophilia B to produce their own factor IX, which can lower the risk of bleeding.
The FDA approval is supported by results from the ongoing HOPE-B trial, the largest gene therapy trial in hemophilia B to date. Results from the study demonstrated that HEMGENIX allowed patients to produce mean factor IX activity of 39 percent at six months and 36.7 percent at 24 months post infusion. Seven to 18 months post-infusion, the mean adjusted annualized bleeding rate (ABR) for all bleeds was reduced by 54 percent compared to the six-month lead-in period on factor IX prophylactic replacement therapy (4.1 to 1.9). In addition, 94 percent (51 out of 54) of patients treated with HEMGENIX discontinued use of prophylaxis and remained free of previous continuous routine prophylaxis therapy. The most common side effects (incidence ≥5%) were liver enzyme elevations, headache, elevated levels of a certain blood enzyme, flu-like symptoms, infusion-related reactions, fatigue, nausea and feeling unwell.
CSL Behring, a CSL business, will make HEMGENIX available for eligible people with hemophilia B as soon as possible.
HEMGENIX is still currently under assessment by other regulatory agencies.
About Hemophilia B
Hemophilia B is a life-threatening rare disease. People with the condition are particularly vulnerable to bleeds in their joints, muscles, and internal organs, leading to pain, swelling, and joint damage. Current treatments for moderate to severe hemophilia B include life-long prophylactic infusions of factor IX to temporarily replace or supplement low levels of the blood-clotting factor.
About HEMGENIX
HEMGENIX is a gene therapy that reduces the rate of abnormal bleeding in eligible people with hemophilia B by enabling the body to continuously produce factor IX, the deficient associated virus (AAV). The AAV5 vector carries the Padua gene variant of Factor IX (FIX-Padua) to the target cells in the liver, generating factor IX proteins that are 5x-8x more active than normal. These genetic instructions remain in the target cells, but generally do not become a part of a person’s own DNA. Once delivered, the new genetic instructions allow the cellular machinery to produce stable levels of factor IX.
