The extended label approval is based on full evidence from the XTEND-Kids study.
The FDA has approved an updated label for ALTUVIIIO [Antihemophilic Factor (Recombinant), Fc-VWF-XTEN Fusion Protein-ehtl] (Sanofi) with new data demonstrating that once-weekly dosing provides bleed protection in children with hemophilia A.1
In February 2023, ALTUVIIIO was approved for children and adults with hemophilia A for routine prophylaxis and on-demand treatment to control bleeding episodes.1
The first-in-class high-sustained factor VIII therapy is designed to extend protection from bleeds with once-weekly prophylactic dosing for hemophilia A patients. The therapy in adolescents has a 3- to 4-fold longer half-life relative to standard and extended half-life factor VIII products, according to Sanofi.1
"Hemophilia is a lifelong condition, so starting children on an early prophylactic regimen can help them stay ahead of bleeds and reduce other potential complications, such as joint damage and pain," said Mindy Simpson, MD, pediatric hematologist/oncologist, assistant professor of pediatrics, Rush University Medical Center, in a press release from Sanofi. "Delivering significant bleed protection with a reduced treatment burden can allow families to spend more time on activities and less time focused on infusion schedules," Simpson said.1
The updated label approval includes full results from the phase 3 XTEND-Kids study (NCT04759131), part of the XTEND clinical program, which also includes the phase 3 XTEND-1 trial (NCT04161495) in individuals aged 12 years and older and the ongoing XTEND-ed extension study.1
Data from the XTEND-Kids study demonstrated that a once-weekly 50 IU/kg dose of ALTUVIIIO provides highly effective bleed protection in children with hemophilia A, according to Sanofi. The trial safety, efficacy, and pharmacokinetics of once-weekly ALTUVIIIO 50 IU/kg in previously treated patients younger than 12 years with severe hemophilia A. Patients received ALTUVIIIO (n = 72) for 52 weeks. The primary endpoint was the occurrence of inhibitor development.1
The primary safety endpoint was met, with no factor VIII inhibitor development detected (0% [95% CI: 0-49]). The mean ABR of 0.6 (95% CI: 0.4-0.9) was observed, a key secondary endpoint. A median ABR of 0.0 (IQR 0.0-1.0) was observed in the study, another key secondary outcome.1
The phase 3 XTEND-1 study was an open-label, nonrandomized interventional study that assessed efficacy, safety and pharmacokinetics of ALTUVIIIO in individuals 12 years and older (n = 159) with severe hemophilia A who were previously treated with factor VIII replacement therapy.1
Two parallel treatment arms made up the study. The prophylaxis Arm A (n = 133) featured patients who had received previous factor VIII prophylaxis that were treated with once-weekly intravenous ALTUVIIIO prophylaxis for 52 weeks (50 IU/kg). The on-demand Arm B (n = 26) featured patients who received prior on-demond factor VIII therapy began with 26 weeks of on-demand ALTUVIIIO 50 IU/kg, then switched to once-weekly prophylaxis with ALTUVIIIO 50 IU/kg for an additional 26 weeks.1
ALTUVIIIO was granded Breakthrough Therapy Designation by the FDA in May of 2022, making it the first factor VIII therapy to receive this designation from the federal agency., In 2021, ALTUVIIIO received Fast Track Designation after receiving Orphan Drug designation in 2017.1
According to the federal agency, Fast Track Designation is designed to facilitate the development and expedite the review of drugs to treat serious conditions and fill an unmet medical need. Breakthrough therapy also exists to expedite the development and review of drugs that could demonstrate "substantial improvement" over available therapy.2
Patients should not use ALTUVIIIO if they had an allergic reaction to it in the past. Symptoms can include chest tightness, difficulty breathing, swelling of the face, rash, or hives.1
Reference:
1. FDA approves updated ALTUVIIIO label with expanded pediatric data confirming highly effective bleed protection in children with hemophilia A. Sanofi. Press release. May 10, 2024. Accessed May 13, 2024. https://www.news.sanofi.us/2024-05-10-FDA-approves-updated-ALTUVIIIO-R-label-with-expanded-pediatric-data-confirming-highly-effective-bleed-protection-in-children-with-hemophilia-A
2. Fast Track, Breakthrough Therapy, Accelerated Approval, Priority Review. FDA. Updated June 12, 2023. Accessed May 13, 2024. https://www.fda.gov/patients/learn-about-drug-and-device-approvals/fast-track-breakthrough-therapy-accelerated-approval-priority-review