The U.S. Food and Drug Administration has approved efanesoctocog alfa for routine prophylaxis and on-demand treatment to control bleeding episodes, as well as perioperative management (surgery) for adults and children with hemophilia A.

Angela Weyand, MD, Associate Professor at Michigan Medicine, discusses recent data published in The New England Journal of Medicine that led to that approval. 

Hemophilia A is a rare bleeding disorder in which the ability of a person’s blood to clot is impaired due to a lack of factor VIII. Hemophilia A occurs mostly in males. People with hemophilia can experience bleeding episodes that can cause pain, irreversible joint damage and life-threatening hemorrhages. Factor replacement therapy remains a cornerstone of care and can be used across multiple treatment scenarios.

The FDA approval was largely based on data from the XTEND-1 study. As Dr. Weyand explains, XTEND-1 is a phase 3 study evaluating the safety, efficacy and pharmacokinetics of efanesoctocog alfa, an investigational factor VIII replacement therapy, in previously treated adults and adolescents ≥12 years with severe hemophilia A.

Based on the data published, efanesoctocog alfa met primary and key secondary endpoints, demonstrating clinically meaningful prevention of bleeds and superior bleed protection compared to prior factor VIII prophylaxis. Treatment with efanesoctocog alfa resulted in significant and clinically meaningful improvements in physical health, pain, and joint health. The median and mean annualized bleeding rates (ABR) were 0.00 and 0.71, respectively, and a statistically significant and clinically meaningful reduction in ABR (77%) was found compared to prior factor VIII prophylaxis (p<0.001). Nearly all (97%) bleeding episodes resolved with a single injection of efanesoctocog alfa (50 IU/kg). Finally, efanesoctocog alfa provided mean factor activity >40 IU/dL for the majority of the week and at 15 IU/dL at Day 7. 

In patients with target joints at baseline, 100% of the target joints were resolved after ≥12 months of continuous prophylaxis. Overall, efanesoctocog alfa was well-tolerated, and inhibitor development to factor VIII was not detected. The most common treatment-emergent adverse events (>5% of participants overall) were headache, arthralgia, falls, and back pain.

To learn more about the mechanism of action of elfanescotocog alfa, please listen to our interview with Annette von Drygalski, MD, PharmD, Director of the Hemophilia and Thrombosis Treatment Center at the University of California, San Diego,

To learn more about hemophilia A and other rare hematological disorders, visit checkrare.com/diseases/hematologic-disorders/