Among patients with severe hemophilia A, once-weekly efanesoctocog alfa may yield high sustained factor VIII (FVIII) activity and improve bleed protection, according to research published in Blood Advances.

Hemophilia A is typically treated with prophylaxis, which reduces the risk of bleeding, in turn lowering the rate of joint damage. The standard FVIII replacement therapies typically require injection every 3 to 5 days.

As yet, however, there is not an approved replacement therapy that leads to sustained, higher activity levels with once-weekly dosage. For this phase 1 repeat-dose study, researchers evaluated the safety, tolerability, and pharmacokinetics of efanesoctocog alfa as a once-weekly prophylactic therapy among patients with severe hemophilia A.

Continue Reading

The study consisted of 2 cohorts: the first received 150 IU/kg efanesoctocog alfa; the second received 265 IU/kg efanesoctocog alfa. In cohorts 1 and 2, 10 and 14 patients were enrolled, respectively; the mean ages were 35 and 41 years, 100% in both groups were White, and the mean time periods since hemophilia diagnosis were 34.1 and 38.8 years.

All patients who were enrolled completed the study. Analysis showed that no FVIII inhibitor development occurred. After the final treatment dose, the geometric mean FVIII activity half-life in cohorts 1 vs 2 was 41.3 vs 37.3 hours, respectively; the steady-state maximum concentration was 131 vs 171 IU/dL.

In cohort 1 vs 2, the mean FVIII activity was 46% vs 69%, respectively, on day 3 after therapy. “Overall, 4 once-weekly doses of efanesoctocog alfa were well tolerated and provided high sustained FVIII activity levels with minimal accumulation,” the authors wrote. “These results suggest that efanesoctocog alfa may offer extended bleed protection with less frequent dosing for individuals with severe hemophilia A and support continued development of efanesoctocog alfa in ongoing phase 3 studies.”

Disclosure: The study author(s) declared affiliations with biotech, pharmaceutical, or device companies. Please see the original reference for a full list of authors’ disclosures. 


Lissitchkov T, Willemze A, Katragadda S, Rice K, Poloskey S, Benson C. Efanesoctocog alfa for hemophilia A: results from a phase 1 repeat-dose study. Blood Adv. 2022;6(4):1089-1094. doi:10.1182/bloodadvances.2021006119