Roche's Hemlibra Wins Expanded FDA Approval, Opening The Door To Broad Hemophilia A Opportunity

Hemlibra was approved to prevent or reduce bleeding in adults and children with hemophilia A without factor VIII inhibitors, a significantly larger patient population than its current indication in patients with factor VIII inhibitors.

An expanded indication for Roche's Hemlibra (emicizumab-kxwh) to prevent or reduce bleeding episodes in adults and children with hemophilia A without factor VIII inhibitors will significantly increase the commercial opportunity for the drug. The Swiss drug maker announced the FDA approval of Hemlibra for routine prophylaxis in the expanded population Oct. 4.

Hemlibra was originally approved in the US for hemophilia A in patients with factor VIII inhibitors in November 2017, but the initial approval was for a small subset of the market. Inhibitors are antibodies that develop when the immune system views infused clotting factor as a foreign substance to be attacked, before it has time to stop the bleeding. Inhibitors are more common in severe hemophilia, but only occur in about 5%-7% of all people with hemophilia A. About 20,000 people in the US have hemophilia, the majority of which have hemophilia A, according to Roche.

Now, Hemlibra will be the only prophylactic treatment for all people with hemophilia A, with and without inhibitors. It is also dosed subcutaneously and administered at different dosing options (once weekly, every two weeks or every four weeks). Other treatment options for people with hemophilia A require intravenous infusions more than once per week.

Hemlibra - originated and licensed to Roche by the Swiss company's Japanese affiliate Chugai Pharmaceutical Co. Ltd.  - is poised to be a competitive force in the hemophilia market, given strong efficacy and convenient administration. It works differently from current factor VIII replacement therapies as a bispecific factor IXa- and factor X-directed antibody. The two factor proteins are required to activate the natural coagulation cascade and restore the blood-clotting process for patients.

Roche priced the drug at launch at a 50% discount to the only other treatment approved for patients with inhibitors, Shire PLC's Feiba (anti-inhibitor coagulation complex), at a wholesale acquisition cost of $492,000 a year after the first year, which includes an extra loading dose (with prices based on the average patient weight). (Also see "Roche's Hemlibra Priced And Labeled To Beat Competition, Safety Concern" - Scrip, 17 Nov, 2017.)

Feiba has been the standard of care for hemophilia A patients with inhibitors. However, the expanded approval of Hemlibra is expected to impact more rival factor replacement therapies, including Sanofi's Eloctate, acquired earlier this year with Bioverativ Inc., Shire's Advate and Adynovate, and Bayer AG's Kogenate, Kovaltry and the newly launched long-acting Jivi. (Also see "Bayer To Ship Long-Acting Hemophilia Infusion Jivi In A Jiffy" - Scrip, 30 Aug, 2018.)

Roche said the annual WAC of Hemlibra for an average weight person with hemophilia A is less than the annual WAC of the two most commonly used prophylactic treatments for people without factor VIII inhibitors, Eloctate and Advate.

The FDA approval is based on two Phase III studies, HAVEN 3 and HAVEN 4. In HAVEN 3, adults and adolescents age 12 and older with hemophilia A without factor VIII inhibitors who received Hemlibra once weekly or every two weeks experienced a 96% and 97% reduction, respectively, in treated bleeds, compared to those who received no prophylaxis. The single-arm HAVEN 4 trial tested Hemlibra prophylaxis every four weeks in adults and adolescents 12 and older with factor VIII inhibitors and without, demonstrating clinically meaningful bleeding control.