The is a Phase 3 study for children, ages 0-17 years old, with severe von Willebrand disease (VWD). In this study, the study drug will be used prophylactically for the treatment of bleeding events. Prophylactic treatment means the study drug will be used to prevent or stop a bleed before it happens.
This study is going to look at how safe the study drug is and how well the study drug (recombinant von Willebrand factor (rVWF, vonicog alfa)), works to prevent and control bleeding.

Vaso-occulsive crisis is a complication of Sickle cell disease in which the red blood cells (RBC) change shape, causing congestion within the blood vessels that leads to pain and tissue damage.

The study medication FT-4202, an oral tablet, is believed to reduce the rate of sickle cell polymerization and improve RBC membrane function, thereby reduction sickling of RBCs and their hemolysis (breakdown of red cells) that causes vascular obstruction and anemia.

This study will consist of a 52-week, randomized (volunteers are selected by chance to receive study either study medication or placebo) , placebo controlled (a placebo is a look-alike pill that contains no active medication). There will be 17 study visits.

The study is followed by a 52-week open label extension study in which all participants will receive study medication. There will be 11 study visits.

This is a study to determine the use of recombinant Von Willebrand Factor (rVWF) in the treatment and control of nonsurgical bleeding episodes and bleeding during elective and emergency surgery in children with severe Von Willebrand Disease. The study will last approximately 14 months and will involve regular visits to a research clinic.