ALPROLIX – Recombinant Factor IX Fc Fusion Protein – Resolved Joint Bleeds in Hemophilia B
Nisha Jain, Director
Global Medical at Biogen

Regarding: Post Hoc Analysis to Evaluate the Effect of Recombinant Factor IX Fc Fusion Protein (rFIXFc) Prophylaxis in Adults and Adolescents with Target Joints and Hemophilia B being presented at the World Federation of Hemophilia (WFH) 2016 World Congress What is the background for this study?

Response: People with hemophilia B experience prolonged bleeding episodes that can cause pain, irreversible joint damage and life-threatening hemorrhages. For people with severe hemophilia, most bleeding events occur in joints, with joint damage being the most common complication of the condition.(1) Over time, joints can become severely damaged and an individual can suffer from acute pain as well as restricted range of motion in those joints.(1) What are the main findings?

Response: The B-LONG and B-YOND trials evaluated ALPROLIX® in hemophilia B patients. In this post-hoc analysis of 37 patients with target joints in B-LONG and B-YOND, most (98.9%) target joints were considered resolved using the International Society on Thrombosis and Haemostasis (ISTH) definition of resolution as ≤ 2 bleeds into the joint within a consecutive 12-month period. What should readers take away from your report?

Response : The hemophilia B patients in this post-hoc analysis used ALPROLIX prophylactically (median dosing interval of 7 days) and showed resolution of target joints. Although adherence to long term prophylactic treatment with traditional treatments has been shown to improve outcomes, it may be more easily achieved with a prolonged half-life factor therapy such as ALPROLIX. In this analysis, target joints were resolved after treatment with ALPROLIX. We are interested in exploring properties associated with Fc fusion technology that may be conferred through binding to Fc receptors. Additional studies are needed to further understand these properties and if they play a role in the healing of target joints and/or preservation of joint health in those without target joints. What recommendations do you have for future research as a result of this study?

Response: Joint deterioration remains one of the most significant morbidities experienced by hemophilia patients. Appropriate management of joint disease, with a focus on improving overall joint health, should be a continued area of focus for management of these patients. As such, we welcome continued research in this area and hope that future studies will increase our understanding of Fc fusion technology and its potential benefits on joint health.

(1) Hemophilia Federation of America. Joint Damage. Available at: Accessed on July 6, 2016.
(2) National Hemophilia Foundation. MASAC Recommendation Concerning Prophylaxis. Available at: Accessed on June 17, 2016.

Citation: Kulkarni, R, Pasi, K. John. et al. Post Hoc Analysis to Evaluate the Effect of Recombinant Factor IX Fc Fusion Protein (rFIXFc) Prophylaxis in Adults and Adolescents with Target Joints and Hemophilia B. World Federation of Hemophilia World Congress. 2016.

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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