The primary objective of this expanded access program (EAP) is to address a significant patient unmet medical need by providing access to bulevirtide (BLV [GS-4438], Hepcludex®) 10 mg for patients in the United States of America (USA) living with chronic hepatitis delta virus (HDV) infection (CHD).

This research study is being done because therapeutic options for people with CHD are severely limited, with no currently approved treatment available for people living with CHD in the US. Study drug bulevirtide is experimental which means that it is being tested and is not approved by the United States Food and Drug Administration (FDA).

The main procedures involve drug injection every day and imaging scans. Participants will provide blood samples and scans of their liver. Eligible patients may receive BLV 10 mg/day up to 96 weeks. The total program duration may last up to 96 weeks, as long as associated with clinical benefit and considered necessary by the treating physician.