FDA Accepts Supplemental Biologics License Application of Altuviiio for Children With Severe Hemophilia A

The FDA has accepted a supplemental biologics license application (sBLA) for antihemophilic factor (recombinant), Fc-VWF-XTEN fusion protein-ehtl (Altuviiio; Sanofi) for children with severe hemophilia A. The sBLA was based on positive results from the phase 3 XTEND-Kids study (NCT04759131), demonstrating highly effective bleed protection with once-weekly dosing. A Prescription Drug User Fee Act action date was set for May 10, 2024.

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“In the [United States], treatment advances over time have given children living with hemophilia the opportunity to move from watching sports as a spectator to becoming an active participant with certain limitations and considerations. With [antihemophilic factor (recombinant)], we are building on this momentum by offering a first-of-its-kind option with proven bleed protection and reduced treatment burden for health care providers and caregivers of children with hemophilia A,” Jeff Schaffnit, head of US Rare Blood Disorders at Sanofi, said in a statement.

Antihemophilic factor (recombinant) is a first-in-class, high sustained factor VIII replacement therapy. It is indicated for use in adults and children with hemophilia A for routine prophylaxis and as on-demand treatment to control bleeding episodes and as perioperative management for surgery.

The sBLA was supported by the results of the XTEND-Kids study, which demonstrated that a once weekly 50 IU/kg dose of antihemophilic factor (recombinant) provides effective bleed protection in children with hemophilia A and can be used across clinical scenarios.

The study included 74 individuals who received the dosages as a prophylaxis for 52 weeks. The drug met the primary endpoint of no factor VIII inhibitor development detected. Furthermore, the study met its key secondary endpoints with median and mean annualized bleeding rates of 0.00 and 0.89, respectively.

The maintenance of factor levels in the normal or near normal range for approximately 3 days was also reached, according to the results of the study. The safety profile was consistent to the XTEND-1 trial, confirming efficacy in both adults and children. There were no serious allergic reactions, anaphylaxis, embolic, or thrombotic events reported. Investigators did not find that the formation of inhibitors and allergic reactions are possible on antihemophilic factor (recombinant).

The most common treatment-emergent adverse events included SARS-CoV-2 positive tests, upper respiratory tract infection, and fever, according to the statement; however, there were no adverse events that led to treatment discontinuation. The FDA approval occurred in February 2023, which was supported by the interim data from the XTEND-Kids open-label non-randomized study. The study evaluated the safety, efficacy, and pharmacokinetics of antihemophilic factor (recombinant) as a once weekly prophylaxis in children who were previously treated and are under 12 years old with severe hemophilia A.

Additionally, the FDA granted breakthrough therapy designation in May 2022, making it the first factor VIII therapy to receive the designation. It also received fast track designation in February 2021 and orphan drug designation in 2018. The European Commission also granted antihemophilic factor (recombinant) orphan drug designation in June 2019.

Although the current label does include the use of the drug for adults and children, the sBLA will update the prescribing information with the final study results, presented as a late-breaker session at the Annual Meeting of the International Society on Thrombosis and Hemostasis in Montreal, Canada.

Reference

Altuviiio supplemental biologics license application based on positive final results from Phase 3 XTEND-Kids study accepted by FDA. News release. Sanofi. September 12, 2023. Accessed September 13, 2023. https://www.news.sanofi.us/2023-09-12-ALTUVIIIO-R-supplemental-biologics-license-application-based-on-positive-final-results-from-Phase-3-XTEND-Kids-study-accepted-by-FDA.