Study of Bulevirtide in Participants With Chronic Hepatitis D Infection

Key Inclusion Criteria: * Individuals who have been diagnosed with chronic hepatitis D virus (HDV) infection for at least 6 months before study enrollment, confirmed by respective documentation in the individuals' medical records. * Must have the ability to understand and sign a written informed consent form, which must be obtained prior to initiation of study procedures. * Must be willing and able to comply with the visit schedule and study requirements. * Cohort 1 only: Must have participated in study MYR-Reg-02. * Cohort 2 only: Individuals scheduled to receive bulevirtide (BLV) according to the approved label or for whom the decision to start treatment with BLV according to the approved label has been made and treatment initiation is planned. Key Exclusion Criteria: * Individuals currently enrolled in BLV clinical treatment studies and/or other interventional clinical studies with an investigational agent. * History or current presence of clinically significant illness or any other major medical disorder that may interfere with individual follow-up, assessments, or compliance with the protocol. * Coinfection with hepatitis C virus (HCV) or human immunodeficiency virus (HIV) (Individuals with HCV antibodies can be enrolled if HCV RNA is negative). * Solid organ transplantation. * Any history, or current evidence of clinical hepatic decompensation (ie, ascites, encephalopathy, jaundice, or gastrointestinal bleeding (GIB)). * Presence of hepatocellular carcinoma (HCC) as …