This clinical trial is focused on studying the long-term effects of a medication called odevixibat (also known by its code name A4250) in children with a liver disease known as biliary atresia. Biliary atresia is a condition that affects the bile ducts, which are tubes that carry bile from the liver to the gallbladder. In this disease, the bile ducts are blocked or absent, leading to liver damage. The purpose of the study is to evaluate how well odevixibat works over a long period and to ensure it is safe for children with this condition.

Participants in the study will take odevixibat in the form of a capsule, which is taken by mouth. The study will follow the children over a period of time to monitor their liver health and overall growth. The main focus will be on how long the children can maintain their liver function without needing a liver transplant or experiencing severe liver problems. The study will also look at changes in certain blood tests that indicate liver health, as well as the children’s growth and development compared to standard growth charts.

The study is an extension of a previous trial, meaning it will continue to observe children who have already been taking odevixibat to see if the benefits are sustained over time. The researchers will collect data at various points throughout the study to assess the medication’s impact on liver health and overall well-being. This information will help determine if odevixibat is a viable long-term treatment option for children with biliary atresia.