FDA Approves Factor VIII Replacement Therapy for Hemophilia A

The US Food and Drug Administration (FDA) has approved antihemophilic factor (recombinant), Fc-VWF-XTEN fusion protein-ehtl, known by the branded name Altuviiio, for use in patients with hemophilia A. Sanofi announced the approval in a press release.¹

Hemophilia A is a genetic disorder caused by a lack or decrease of clotting factor VIII. The Centers for Disease Control and Prevention (CDC) estimate that up to 33,000 male individuals in the United States were living with hemophilia A between 2012 and 2018. People with hemophilia A experience excessive and spontaneous bleeding which can lead to joint damage, seizures and paralysis, and death.²

Per the CDC, “Hemophilia A is about 4 times as common as hemophilia B, and about half of those affected have the severe form.” 

Altuviiio was approved for the following uses in children and adults with hemophilia A:

• routine prophylaxis to reduce the frequency of bleeding episodes;
• on-demand treatment and control of bleeding episodes; and
• perioperative management of bleeding.

The FDA’s decision was based on data from the XTEND-1 study, a phase 3 trial in which patients with severe hemophilia A received once-weekly Altuviiio prophylaxis. 

Treatment with Altuviiio lowered the risk of bleeding by producing factor VIII activity greater than 40% for most of the week and greater than 10% on Day 7. Additionally, Altuviiio was associated with a mean annualized bleeding rate (ABR) of 0.70 (95% CI: 0.5 to 1.0), a median ABR of 0.0 (Q1, Q3: 0.0, 1.0), and a median annualized joint bleeding rate of 0 (Q1, Q3: 0.0, 1.0).

“This approval marks an important clinical advancement for the hemophilia community because we have an option that can achieve higher levels of factor activity with a single simplified weekly dose,” said Lynn Malec, MD, medical director, Comprehensive Center for Bleeding Disorders; associate investigator, Versiti Blood Research Institute; and associate professor of medicine and pediatrics, Medical College of Wisconsin.

The most common side effects of Altuviiio, occurring in more than 10% of patients, are headache and arthralgia. Factor VIII inhibitor development may also occur but was not reported in any studies.

Altuviiio is expected to hit the US market in April 2023.

References:

1. FDA approves once-weekly ALTUVIIIO™, a new class of factor VIII therapy for hemophilia A that offers significant bleed protection. News release. Sanofi; February 23, 2023. Accessed March 9, 2023. https://www.sanofi.com/en/media-room/press-releases/2023/2023-02-23-21-00-00-2614759
2. What is hemophilia? Centers for Disease Control and Prevention. Reviewed August 1, 2022. Accessed March 9, 2023. https://www.cdc.gov/ncbddd/hemophilia/facts.html