What is haemophilia A?
The clotting cascade
Clotting factors interact with each other in a sequence – think of them like a set of dominoes.
This is a bit like having a domino missing.
People with haemophilia A are often given factor VIII replacement therapy.
This medicine is used to replace missing factor VIII. It can help make your blood clot and stop bleeds.
This medicine can be really helpful for people with haemophilia A, but sometimes it can stop working. This is because factor VIII is not made by your body. Your body can sometimes think that the factor VIII replacement therapy does not belong there. As a result, inhibitors can form.
What are inhibitors?
Inhibitors are antibodies that stick to factor VIII in the medicine. When this happens, you have ‘haemophilia A with inhibitors to factor VIII’.
Like you and Michael, one in three people with severe haemophilia A start to make inhibitors to factor VIII at some point in their lives.
Remember the dominoes?
The inhibitors stick to factor VIII, taking the domino out of the chain. This means the blood cannot clot properly.
Inhibitors are a type of antibody
Antibodies are a normal part of your blood that help fight infection. They help to protect you by recognising and sticking to things that shouldn’t be in your body, such as bacteria or ‘germs’.
Antibodies can also be made in a laboratory and used as medicines.
Hemlibra is a type of antibody, called a monoclonal antibody that can help people with haemophilia A with inhibitors to factor VIII. It should still work even if you have inhibitors to factor VIII.
Hemlibra sticks to two clotting factors, factor IXa (activated factor 9) and factor X (factor 10).
