NEJM publishes ALTUVOCT® phase 3 XTEND-Kids results highlighting treatment potential for children with severe haemophilia A

• XTEND-Kids is the first assessment of once-weekly ALTUVOCT® prophylaxis in previously treated children
• Results indicate highly effective bleed protection in children under 12 years of age with severe haemophilia A

Sobi® today announced the publication of full results from the Phase 3 XTEND-Kids study in The New England Journal of Medicine (NEJM) confirming the safety and efficacy profile of ALTUVOCT® (efanesoctocog alfa), in children younger than 12 years old with severe haemophilia A. The study demonstrated that fixed-dose once-weekly prophylaxis with ALTUVOCT, a new class of high-sustained factor VIII therapy, provided highly effective bleed protection in children.

“Children represent a population for which it has been historically difficult to achieve effective bleed prevention,” said Lynn Malec, MD, Medical Director of Comprehensive Center for Bleeding Disorders and Associate Investigator at The Versiti Blood Research Institute, and Associate Professor of Medicine and Paediatrics at The Medical College of Wisconsin. “The clearance of administered factor concentrates is greater in children than we see in adults, which leads to burdensome treatment regimens involving multiple injections per week. By providing high-sustained factor VIII activity levels consistently early in life with once-weekly dosing, ALTUVOCT has the potential to improve reported outcomes for children living with haemophilia.”

Published in NEJM, the pivotal XTEND-Kids study shows ALTUVOCT met primary and key secondary endpoints, which included occurrence of factor VIII inhibitors and annualised bleed rates (ABRs). Results revealed no development of factor VIII inhibitors and sustained protection from bleeding events with once-weekly dosing. These findings support the value of sustaining high factor levels with ALTUVOCT in children with haemophilia A.

“The recent XTEND-Kids study further underscores the safety and effectiveness of ALTUVOCT, showcasing how high-sustained factor VIII activity can improve clinical outcomes in children,” said Lydia Abad-Franch, MBA, Head of Research, Development, and Medical Affairs, and Chief Medical Officer at Sobi. “Maintaining normal factor VIII levels in the non-haemophilia range for a significant part of the week effectively reduces the occurrence of any type of bleed and enables people with haemophilia to lead more active lives. Today’s announcement reinforces our enduring commitment to transforming standards of care across all ages within the haemophilia community."

For patients treated per protocol (n=73), the estimated mean (95% CI) and median [interquartile range (IQR)] overall ABRs were 0.61 (0.42–0.90) and 0.00 (0.00–1.02), respectively. In 95% of cases bleeding episodes (41/43) resolved with one ALTUVOCT injection. The majority (64%) of patients had zero bleeding episodes, 84% of patients had zero joint bleeds and 88% of patients had zero spontaneous bleeds. ALTUVOCT prophylaxis provided high-sustained factor VIII activity in the non-haemophilia range (above 40%) for three days.

In the study, ALTUVOCT was well tolerated. Development of factor VIII inhibitors was not detected (0% [95% confidence interval (CI)] 0–4.9]), and no adverse events led to treatment discontinuation. The most common treatment-emergent adverse events (>10%) were SARS-CoV-2 test positive, upper respiratory tract infection, and fever (pyrexia). No serious allergic reactions, anaphylaxis, or embolic or thrombotic events were reported.
 

About Haemophilia A
Haemophilia A is a rare, lifelong genetic condition in which the body does not produce enough, or makes dysfunctional, factor VIII – a protein that is essential for blood clotting. It occurs in about one in 5,000 male births annually, and more rarely in females. People with haemophilia can experience bleeding episodes that can cause pain, irreversible joint damage and life-threatening haemorrhages.

About XTEND-Kids
XTEND-Kids was an open-label, non-randomised interventional, single-arm study. Participants received a weekly prophylactic dose of ALTUVOCT® for 52 weeks. XTEND-Kids evaluates efficacy, safety, and pharmacokinetics in 74 previously treated patients <12 years of age with severe haemophilia A.

About ALTUVOCT®

ALTUVOCT® (efanesoctocog alfa) [Antihemophilic Factor (Recombinant), Fc-VWF-XTEN Fusion Protein] (formerly BIVV001) is the first high-sustained FVIII replacement therapy with the potential to deliver near-normal factor activity levels for a significant part of the week, improving bleed protection in a once-weekly dose for people with haemophilia A. ALTUVOCT builds on the established Fc fusion technology by innovatively adding a region of von Willebrand factor and XTEN® polypeptides to extend its time in circulation. It is the only therapy that has been shown to break through the von Willebrand factor ceiling, which imposes a half-life limitation on current factor VIII therapies. The European Commission granted Orphan Drug designation in June 2019. It is approved and marketed as ALTUVOCT by Sobi in Europe. It is approved and marketed as ALTUVIIIO™ [Antihemophilic Factor (Recombinant), Fc-VWF-XTEN Fusion Protein-ehtl] by Sanofi in the United States, Japan, and Taiwan.

About the Sanofi and Sobi collaboration

Sobi and Sanofi collaborate on the development and commercialisation of Alprolix® and Elocta®/Eloctate®. The companies also collaborate on the development and commercialisation of ALTUVOCT® (efanesoctocog alfa), or ALTUVIIIO™ in the US. Sobi has final development and commercialisation rights in the Sobi territory (essentially Europe, North Africa, Russia, and most Middle Eastern markets). Sanofi has final development and commercialisation rights in North America and all other regions in the world excluding the Sobi territory.

About Sanofi

We are an innovative global healthcare company, driven by one purpose: we chase the miracles of science to improve people’s lives. Our team, across some 100 countries, is dedicated to transforming the practice of medicine by working to turn the impossible into the possible. We provide potentially life-changing treatment options and life-saving vaccine protection to millions of people globally, while putting sustainability and social responsibility at the centre of our ambitions. Sanofi is listed on EURONEXT: SAN and NASDAQ: SNY

Sobi®

Sobi® is a specialised international biopharmaceutical company transforming the lives of people with rare and debilitating diseases. Providing reliable access to innovative medicines in the areas of haematology, immunology, and specialty care, Sobi has approximately 1,800 employees across Europe, North America, the Middle East, Asia, and Australia. In 2023, revenue amounted to SEK 22.1 billion. Sobi's share (STO:SOBI) is listed on Nasdaq Stockholm. More about Sobi at sobi.com and LinkedIn.

Contacts

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Phone: 46 8 697 20 00     https://www.sobi.com