A Study Observing the Long-term, Effectiveness and Safety of Odevixibat (Bylvay) in Patients With Alagille Syndrome (ALGS) Who Are Receiving Ongoing Treatment

This study will collect information from patients with Alagille syndrome (ALGS) as they use odevixibat (Bylvay) in their daily lives. Odevixibat is a medicine that helps patients with ALGS, a rare disease that harms their liver and causes itching. The main aim of this study is to observe the long-term, everyday effectiveness and safety of the drug odevixibat in patients with ALGS who are receiving ongoing treatment.

Inclusion Criteria: * Diagnosed with ALGS. * On (or starting) active odevixibat treatment. * Signed informed consent and assent, as appropriate. Consent/assent from the participant or legal representative should be obtained, as appropriate, before any study data collection is conducted. Participants who turn 18 years of age (or legal age per country) while participating in the study will be required to provide consent for themselves. Exclusion Criteria: * Currently participating in a clinical trial with odevixibat. * Currently participating in any interventional clinical trial for ALGS. * Have any contraindication to odevixibat as per the locally approved label. * Had liver transplant before enrolment