Altuviiio for Severe Hemophilia A: New Study Confirms Safety and Effectiveness

Altuviiio (efanesoctocog alfa) reduced bleeding and was safe for boys and young men with severe hemophilia A, according to a recent study. Researchers also reported an increase in participants’ confidence in everyday activities and no return of neutralizing antibodies that may inhibit treatment, even in patients who are usually excluded from clinical trials. Patients and their caregivers reported more “confidence to pursue physical activity,” researchers wrote in “Integration of Efanesoctocog Alfa in Clinical Practice for Children, Adolescents, and Young Adults With Severe Haemophilia A,” which was published in Haemophilia. Altuviiio designed to last longer in the body Hemophilia A is caused by mutations in the gene that provides instructions for producing factor VIII (FVIII), a protein needed for blood to clot. When FVIII is defective or absent, blood cannot clot well. As a result, patients experience frequent episodes of excessive bleeding. Factor replacement therapy, which supplies the body with a working version of the clotting protein that is faulty or missing, can prevent or reduce the frequency of bleeding episodes. Standard options usually require two to four injections a week, but Altuviiio is designed to last longer in the body, reducing the need for frequent injections. Altuviiio was approved based on two Phase 3 clinical trials: XTEND-1 (NCT04161495) in patients ages 12 and older and XTEND-Kids (NCT04759131) in patients younger than 12. However, these two studies excluded previously untreated patients, patients on Hemlibra (emicizumab), and those with neutralizing (inhibitor) antibodies against FVIII. Patients had fewer treated bleeding episodes, on average How Altuviiio works in these groups is unclear. To learn more, researchers at Boston Children’s Hospital and Massachusetts General Hospital reviewed the medical records of 23 boys and young men with hemophilia A, with a median age of 16. Their goal was to see how well this treatment works in real-world patients. Sixteen patients (69.6%) switched from preventive treatment with a FVIII concentrate to Altuviiio, while the other seven switched from Hemlibra. One additional patient, a newly diagnosed 2-year-old boy, received a single infusion of Altuviiio to treat a bleeding episode. FVIII activity levels were measured to see how much clotting protein remained in the blood days after an infusion of Altuviiio. In patients switching from a FVIII concentrate, average FVIII levels remained measurable on day six. In those switching from Hemlibra, similar observations were made. Compared with their previous preventive treatment, patients had, on average, fewer treated bleeding episodes (1.3 vs. 0.1) and fewer emergency department visits (0.8 vs. 0.1) per year. These results show that the new treatment provided better bleeding control. Importantly, no patients redeveloped FVIII inhibitors during a median follow-up of 22.6 months, or almost 2 years. This is especially meaningful for patients who previously had FVIII inhibitors, since recurrence is common and may make treatment less effective. Both patients and their caregivers reported less joint and muscle pain, greater confidence that bleeding was well controlled, and greater comfort with physical activity, suggesting that switching to Altuviiio may be effective, even in groups of patients not included in earlier clinical trials.