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Gene therapy — a medical approach that treats diseases by addressing the underlying genetic problem — is ushering in a new era of medicine. With a one-time treatment, gene therapy has the potential to dramatically impact the lives of people living with hemophilia B by reducing annual bleeds and reducing or eliminating the need for infusions. As more gene therapies come to market, the data are bearing out this shift in how we care for patients and how we pay for it.

Recently The Institute for Clinical and Economic Review (ICER) — an independent institute for clinical and economic review — found that gene therapy for hemophilia B is shifting the care and cost paradigm for treating this genetic condition.

According to recent reviews by ICER, gene therapies have the potential to bring value by delivering cost-effective therapies for both patients and the entire healthcare system.

Specifically, hemophilia B, which is a rare genetic disorder characterized by bleeding, pain, and long-term complications, is a gene therapy target because it is caused by a single gene mutation. Hemophilia B is caused by an absence or deficiency in the production of factor IX, a protein primarily produced by the liver that helps blood clot.

The cost and care burden

While current treatments are effective, they can be costly, and patients may still experience ongoing complications from the disease. Currently, many patients must adhere to strict, lifelong prophylactic infusion schedules and may still experience spontaneous bleeding episodes, as well as limited mobility, joint damage or severe pain. Hemophilia B patients experience a range of lifestyle and psychosocial limitations due to pain, impaired mobility, rigid treatment schedules and absences from work or school. In fact, 94% of patients had difficulty ​completing a ​formal education and 95% indicated that ​hemophilia B had a ​negative impact ​on employment.

Additionally, the cost burden for the disease can be high for both patients and the healthcare system overall. Healthcare costs can be 25 times higher for a person living with moderate to severe hemophilia B — amounting to a total adult lifetime cost of more than $20 million per patient.

Data support the value of gene therapy

A new gene therapy for hemophilia B has been shown to reduce annual bleed rates, reduce or eliminate prophylactic therapy and generate elevated and sustained factor IX levels. ICER’s evidence report confirmed the therapy was clinically safe and effective.

Also included in ICER’s report, the organization highlighted the potential long-term impacts of gene therapies and the value that eliminating the need for expensive prophylactic treatments could bring to the healthcare system.

In assessing the value of the therapy, ICER examined multiple cost-effectiveness scenarios. Because the therapy is potentially effective at decreasing or eliminating medical costs in even the most severe patients, ICER’s base case demonstrated that the new therapy would be cost-effective at $9.9 million and could offer significant savings to the overall healthcare system of approximately $6 million or more over the lifetime of a patient, at a hypothetical price of $4 million for treatment. ICER’s durability models predicted clinical effectiveness up to 23 years post-infusion.

The cost-saving potential of the new therapy was made further evident in hypothetical modelling scenarios ICER developed to shed light on the opportunity for new therapies to produce system-level savings. The first of these scenarios, referred to as the “shared savings” model, aims to determine what price would enable half of the cost savings from the standard of care to be allocated to healthcare system cost reductions, rather than being entirely assigned to the therapy. ICER determined that in this scenario, the new gene therapy would be cost-effective up to $5.1 million per treatment. In the second scenario, in which ICER assumes that there is an annual cap of $150,000 on cost offsets per year, the new therapy would be cost-effective at a price of $2.9 million. In each of the scenarios, it is important to note that the prices modeled by ICER do not reflect discounts or rebates, such as those that would be provided through the federal 340B rebate program. In the case of hemophilia B, the 340B discount program helps subsidize critical supportive coordinated care provided by hemophilia treatment centers (HTCs).

Shifting the cost and care paradigm

Gene therapy has the potential to fundamentally transform the treatment paradigm for life-long conditions, such as hemophilia B, providing patients with a new option that has the potential to make near-normal blood clotting ability possible by addressing the cause of the condition. By liberating eligible patients with hemophilia B from living their lives around time-consuming and regimented infusion schedules, reducing the rate of annual bleeds and offering elevated and sustained FIX activity levels, this therapy could provide relief to both patients and the healthcare system.

For more information, visit ICER’s Evidence Report.



HEMGENIX®, etranacogene dezaparvovec-drlb, is a one-time gene therapy 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.

HEMGENIX is administered as a single intravenous infusion and can be administered only once.

What medical testing can I expect to be given before and after administration of HEMGENIX?

To determine your eligibility to receive HEMGENIX, you will be tested for Factor IX inhibitors. If this test result is positive, a retest will be performed 2 weeks later. If both tests are positive for Factor IX inhibitors, your doctor will not administer HEMGENIX to you. If, after administration of HEMGENIX, increased Factor IX activity is not achieved, or bleeding is not controlled, a post-dose test for Factor IX inhibitors will be performed.

HEMGENIX may lead to elevations of liver enzymes in the blood; therefore, ultrasound and other testing will be performed to check on liver health before HEMGENIX can be administered. Following administration of HEMGENIX, your doctor will monitor your liver enzyme levels weekly for at least 3 months. If you have preexisting risk factors for liver cancer, regular liver health testing will continue for 5 years post-administration. Treatment for elevated liver enzymes could include corticosteroids.

What were the most common side effects of HEMGENIX in clinical trials?

In clinical trials for HEMGENIX, the most common side effects reported in more than 5% of patients were liver enzyme elevations, headache, elevated levels of a certain blood enzyme, flu-like symptoms, infusion-related reactions, fatigue, nausea, and feeling unwell. These are not the only side effects possible. Tell your healthcare provider about any side effect you may experience.

What should I watch for during infusion with HEMGENIX?

Your doctor will monitor you for infusion-related reactions during administration of HEMGENIX, as well as for at least 3 hours after the infusion is complete. Symptoms may include chest tightness, headaches, abdominal pain, lightheadedness, flu-like symptoms, shivering, flushing, rash, and elevated blood pressure. If an infusion-related reaction occurs, the doctor may slow or stop the HEMGENIX infusion, resuming at a lower infusion rate once symptoms resolve.

What should I avoid after receiving HEMGENIX?

Small amounts of HEMGENIX may be present in your blood, semen, and other excreted/secreted materials, and it is not known how long this continues. You should not donate blood, organs, tissues, or cells for transplantation after receiving HEMGENIX.

Please see full prescribing information for HEMGENIX.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit, or call 1-800-FDA-1088.

You can also report side effects to CSL Behring’s Pharmacovigilance Department at 1-866-915-6958.