The goal of this study is to provide access to bulevirtide (BLV (GS-4438), Hepcludex®) to eligible participants with chronic hepatitis delta virus infection (CHD).

Key Inclusion Criteria:

• Diagnosed with CHD as confirmed by medical records.
• Compensated liver disease with liver cirrhosis (defined by biopsy, Fibroscan, or clinically by the treating physician) and Child-Pugh score ≤ 6.
• Positive HDV RNA test within 6 months of initial EAP request (only applicable to patients who have not received treatment with BLV).

Key Exclusion Criteria:

• Coinfection with hepatitis C virus (HCV) (HCV viremia defined by polymerase chain reaction (PCR)) or uncontrolled HIV infection (CD4 < 500 cells/mm^3 and detectable HIV RNA).
• Current or previous (within last 3 months from screening) decompensated liver disease, including coagulopathy, hepatic encephalopathy, and esophageal varices hemorrhage.
• Significant medical diseases or conditions, that might decrease the benefit-risk ratio of participating in this program to an unacceptable level, as determined by the treating physician.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.