Approvals of Hemlibra
Montreal, September 13, 2021 – In recent weeks, governments in both Quebec and the rest of Canada have expanded access to Hemlibra to patients with hemophilia A without inhibitors. Unlike factor VIII concentrates, however, Hemlibra will not be available to all people with hemophilia A.
Hemlibra was initially approved in summer 2019 for all those with inhibitors to factor VIII.
Who then is eligible in the regions served by Canadian Blood Services (CBS)?
In the provinces and territories served by CBS (all except Quebec), health authorities expanded access, without age restrictions, to include those with severe congenital hemophilia A (intrinsic factor VIII level < 1%) without inhibitors who are candidates for routine prophylaxis to prevent bleeding or reduce the frequency of bleeding episodes. This means that those people with moderate hemophilia, even those with factor VIII levels just above 1%, are not eligible. All the research studies leading to the licensure of Hemlibra were carried out in people with severe hemophilia A. A factor VIII level of 1% or less is the standard definition of severe hemophilia. Research is only now starting into the efficacy of Hemlibra in populations with factor VIII levels above 1%.
It is becoming better recognized that factor level, as measured by a lab test, is not the only element affecting the severity of clinical symptoms. Other issues, some understood and others not, affect how often and how easily people bleed. Some people with levels below 1% rarely bleed with no apparent cause, while others in the moderate range of 1-5% can suffer from frequent non-traumatic bleeds. It can only be hoped that as research continues and the tendency to consider clinical bleeding as opposed to factor assays measured by lab tests gains acceptance, patients with moderate hemophilia who require prophylaxis will become eligible.
CBS has announced that Hemlibra should be available in hemophilia centers by mid-October.
How does Hemlibra work?
Hemlibra is a monoclonal antibody that performs the same function as factor VIII, the natural protein missing in the blood of people with hemophilia A, which in different forms has been the routine treatment for the last 70 years. Factor VIII is administered both to stop and to prevent bleeding; Hemlibra, however, can only be used to prevent bleeding (prophylaxis). In the event of an active bleed needing treatment, factor VIII would be infused.
Hemlibra is …
- … better than factor VIII at preventing bleeding in most patients with severe hemophilia A. It obtains a constant clotting level equivalent to a factor VIII level of approximately 15%.
- … much easier to take. It is injected subcutaneously (under the skin) rather than intravenously (into a vein), like factor VIII.
- … administered less often, just once a week or less compared to 2 to 7 times per week for factor VIII.