A Study Evaluating Physical Activity and Joint Health in Severe Haemophilia A Patients ≥12 Years Treated Once Weekly With Efanesoctocog Alfa

This study is looking for people aged 12 and older who have severe haemophilia A. To be considered, you should have been treated for haemophilia A before and have been on regular preventative treatment (prophylaxis) for at least the past year. We'll also need to check your past treatment and bleed records.

You'll need to be comfortable using a smartphone for an electronic diary and wearing an activity tracker. You should also be able to safely give yourself the study medicine at home through an injection into a vein (intravenously).

There are also some reasons why you might not be able to join. For example, if you have other serious health conditions that affect your movement, another bleeding disorder besides haemophilia A, or a history of inhibitors (when your body produces antibodies against the treatment). You also shouldn't have had major surgery recently or have one planned during the study, or be taking certain other medications.

If you join the FREEDOM study, you'll first have a `run-in period` of about 1 to 1.5 months. During this time, you'll start using an activity tracker and an electronic diary on your smartphone to record information. After this, you'll begin taking the study medicine, efanesoctocog alfa, once a week for two years (24 months). You won't be able to take extra preventative doses of the medicine.

Throughout the entire study – from the very beginning until the end – you'll continue to use the activity tracker and fill in your electronic diary on your smartphone. This diary will ask about your physical activity, any bleeds you have, how much medicine you take, any pain you feel, and any injuries. You'll also have regular check-ups where doctors will examine your joints and overall health. The total duration of the study, including the initial run-in period, will be a bit over two years.