Hemgenix^® (etranacogene dezaparvovec – drlb) suspension was approvedby the U.S. Food and Drug Administration (FDA) on Nov. 22, 2022. It replaces mutated Factor IX (FIX) genes to treat adults who use Factor IX prophylaxis therapy, or have had severe hemorrhages, or have recurring, serious bleeds due to hemophilia B (congenital Factor IX deficiency). Administered as a single dose of 2×10¹³ genome copies (gc)/kg over one hour as an intravenous (IV) infusion, Hemgenix is manufactured in a laboratory. After filtration, purification, and sterilization, the genetic material of bioengineered non-infective viral cells is replaced with functional FIX genes. Then, the resulting combination is mixed with a promoter agent that targets human liver cells and infused into eligible patients. CSL Behring will distribute Hemgenix in the U.S. beginning as soon as possible through a specialty pharmacy network that includes Accredo. For its full prescribing information, look here.

At a Glance

• Brand (Generic) Name: Hemgenix (etranacogene dezaparvovec-drlb)
• Manufacturer: CSL Behring
• Date Approved: Nov. 22, 2022
• Indication: agene therapy for the treatment of adults who have hemophilia B and who currently use Factor IX prophylaxis therapy, or have current or historical life-threatening hemorrhages, or have repeated, serious spontaneous bleeding episodes
• Dosage Forms Available: kits of between 10 and 48 vials with at least 10mL of suspension at 1×10¹³ genome copies in each — for a weight-based dose of 2×10¹³ genome copies (gc)/kg for each patient
• Launch Date: as soon as possible
• Estimated Cost: Pricing information is not yet available.
• An inherited bleeding disorder, hemophilia B is caused by mutations in the Factor IX gene on X chromosomes. Because patients who have it produce insufficient amounts of clotting Factor IX, they experience bleeding episodes that cause intense pain, permanent joint damage, and potentially life-threatening hemorrhages.
• Less common than hemophilia A, the B form of the condition affects approximately 4,000 patients, including some females, in the United States. Roughly one-third of patients have no family history of the disorder. Approximately 60% of patients have low enough natural FIX amounts to need replacement therapy.
• Hemgenix delivers working copies of an enhanced FIX gene — through a noninfective virus vector — to cells in the liver, which produce FIX.
• In the phase III HOPE-B Gene Therapy Trial, 54 men received Hemgenix. While they continued their usual FIX replacement regimen in the six-month period before their infusions, 38 of the patients had a collective total of 123 bleeds. Six months after treatment, the average increase in FIX was 36%, bleeding episodes were down by 83% and 51 of the patients no longer needed regular FIX infusions to prevent bleeds.
• During the trial, nine participants experienced increases in a liver enzyme, transaminase, which had to be treated with corticosteroids. Mostly mild headaches, flu-like symptoms, and infusion reactions affected seven patients each.
• Currently, hemophilia B is managed by infused FIX replacement – regularly to prevent episodes and as needed to control bleeds that have started.
• Designated as an Orphan Drug for hemophilia B, Hemgenix was approved through the FDA’s Breakthrough Therapy and Priority Review pathways.

Embarc Benefit Protection Strategy: Evernorth is reviewing the clinical efficacy and safety information in addition to the financial impact of CSL Behring’s newly approved gene therapy, Hemgenix, and further evaluation is needed. As such, Evernorth has not yet decided if Hemgenix will be added to Embarc Benefit Protection. The Embarc team will provide confirmation as soon as possible.