Sanofi has reported that its ALTUVIIIO  [Antihemophilic Factor (Recombinant), Fc-VWF-XTEN Fusion Protein] showed promise in the Phase III XTEND-Kids study in children with severe haemophilia A.

The non-randomised, open-label, interventional trial evaluated the effects of ALTUVIIIO given once a week in previously treated 73 subjects aged below 12 years with severe haemophilia A.

Discover B2B Marketing That Performs

Combine business intelligence and editorial excellence to reach engaged professionals across 36 leading media platforms.

Find out more

These subjects received ALTUVIIIO prophylaxis over a one-year period.

The incidence of factor VIII inhibitors was the trial’s primary endpoint with secondary endpoints examining pharmacokinetics, safety, annualised bleed rates (ABRs) and other health measures.

According to the findings, the trial met these endpoints, indicating no development of inhibitors to factor VIII and ABRs.

Data revealed a median ABR of 0.00, with the estimated mean ABR being 0.61 in trial subjects.

GlobalData Strategic Intelligence

US Tariffs are shifting - will you react or anticipate?

Don’t let policy changes catch you off guard. Stay proactive with real-time data and expert analysis.

By GlobalData

In the trial, 82% of the children receiving ALTUVIIIO experienced no joint bleeds, indicating the treatment’s potential to preserve joint health long-term.

ALTUVIIIO was found to be well-tolerated in trial subjects without any adverse events leading to discontinuation of the treatment.

The most common side effects observed were non-serious and included upper respiratory infections and fever.

ALTUVIIIO, also known as efanesoctocog alfa, is approved for use in both adults and children for routine prophylaxis, on-demand bleeding control, and perioperative management.

Sanofi Development global head and chief medical officer Dietmar Berger said: “The XTEND-Kids data validate the connection between high-sustained factor activity levels and improved health outcomes, including joint health. Offering a treatment option that emphasizes effective bleed protection in children with haemophilia can help give families increased peace of mind when their loved ones participate in everyday activities.

“The results are a testament to our scientific expertise and commitment to redefine the standard of care for children living with haemophilia through ALTUVIIIO and our broader portfolio of haemophilia therapies.”

Recently, the company reported data from a Phase II trial of frexalimab in patients with relapsing multiple sclerosis.

Clinical Trials Arena Excellence Awards - Nominations Closed

Nominations are now closed for the Clinical Trials Arena Excellence Awards. A big thanks to all the organisations that entered – your response has been outstanding, showcasing exceptional innovation, leadership, and impact.

Excellence in Action
Recognised with 2025 Excellence Awards for Research and Development and Marketing , Novotech converted FDA/EMA fast track designations into faster HDV trial timelines while translating complex HBV science into sponsor ready insights. Discover how this dual strength in execution and communication is reshaping liver disease clinical development.

Discover the Impact