A Study to Assess the Efficacy and Safety of Emicizumab in Participants With Type 3 Von Willebrand Disease

To join this study, doctors must have already confirmed that you have Type 3 Von Willebrand Disease. They'll also check your past medical notes to see if you have special proteins in your blood (called VWF inhibitors) and make sure your blood, liver, and kidney functions are healthy enough for the study.

For some parts of the study (Arms A and B), you need to be at least one month old and have used 'on-demand' treatment for VWD, meaning you only treat bleeds as they happen, less than once a week. You also should have had at least two bleeds treated with clotting factor medicine in the 24 weeks before joining (not including period bleeds).

For another part of the study (Arm C), you need to be at least two years old and have been receiving regular preventive treatment for VWD (1-3 times a week) for at least 24 weeks as part of a previous study. You can't have other bleeding disorders, a recent history of stomach bleeding, or a history of bleeding in the brain. If you've had blood clots or are at high risk of them, or have certain other medical conditions, you might not be able to join. You also can't be allergic to certain types of medicines called monoclonal antibodies.

If you decide to take part, the amount of time and effort involved will depend on which group you're in. Generally, this is a long-term study, and you would have regular visits to the clinic. During these visits, the study team would check your health, ask about any bleeding episodes you've had, and take blood samples. You would receive the study medication, emicizumab, through an injection under your skin, or continue your current treatment as decided by the study. The study team will explain all the specific details of your appointments, tests, and how long you'll be involved.