Efanesoctocog alfa is the first once-weekly factor VIII (FVIII) replacement intravenous infusion therapy, which will help reduce the burden associated with the injection frequency of other currently available FVIII therapies. For patients reluctant to receive novel therapies, such as mAbs or gene therapy, efanesoctocog alfa will likely be an appealing option. Clinicians also view efanesoctocog alfa favorably given the attainable FVIIII levels, injection frequency and safety profile demonstrated in clinical trials to date.
Sanofi has development and commercialization rights for efanesoctocog alfa in the United States, whereas Swedish Orphan Biovitrum (Sobi) is responsible for developing and marketing the drug in Europe and other markets.
To potentially extend its time in circulation, efanesoctocog alfa adds a region of von Willebrand factor and XTEN® polypeptides to the innovative Fc fusion technology. It is the only therapy that has been shown to break through the von Willebrand factor ceiling, which is believed to impose a half-life limitation on current FVIII therapies. The result is the first FVIII replacement therapy that is administered only once a week, reducing the treatment burden.
The U.S. FDA approval was primarily based on data from the pivotal phase 3 XTEND-1 study conducted over a period of 52 weeks with adult and adolescent (>12 years) patients with severe hemophilia A who had been previously treated with either a FVIII prophylaxis treatment or FVIII on-demand therapy. Patients who were on FVIII prophylaxis pre-study received efanesoctocog alfa for routine prophylaxis (arm A). Patients who received on-demand treatment with FVIII pre-study were assigned to receive on-demand efanesoctocog alfa treatment for 26 weeks, followed by routine prophylaxis once weekly for 26 weeks (arm B). The study results for once weekly efanesoctocog alfa prophylaxis included the following:
The phase 3 XTEND-Kids study was also conducted over 52 weeks with previously treated children (<12 years) with severe hemophilia A and found the following for once weekly efanesoctocog alfa prophylaxis:
Ongoing studies include the following:
August 2017
June 2019
February 2021
July 2021
June 2022
February 2023
For adult and pediatric patients with hemophilia A
May 2023
September 2023
For adult and pediatric patients with hemophilia A
Actual and expected launch:
Patents estimated to expire beginning in 2032
How will efanesoctocog alfa impact the market for hemophilia A?
What gaps in treatment does efanesoctocog alfa fill?
A primary goal in the treatment of hemophilia A is to prevent bleeding, particularly bleeding into the joints, which is associated with permanent joint damage. Another important outcome is better quality of life. However, the dosing frequency and route of administration for current FVIII replacement therapies are burdensome and contribute to suboptimal compliance rates. As the first once-weekly FVIII replacement infusion therapy, efanesoctocog alfa could improve patient convenience, reduce the treatment burden and enhance treatment compliance.
What hurdles might it need to overcome to reach blockbuster status?
Treating hemophilia is expensive, especially for patients with severe bleeding tendencies, and both clinicians and payers are asking for precise quantification of the value of a treatment regimen. As a lower-cost subcutaneously administered treatment option that is currently available for patients, HEMLIBRA® (Genentech) continues to constrain the value of the market with its increasing adoption. Although also likely to be costly initially, emerging gene therapies could be curative and reduce the need for invasive standard treatments, such as FVIII replacement therapy.
– Source: Cortellis Competitive Intelligence, Drug Timeline & Success Rates Prediction current as of November 3, 2023
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