Overview
The goals of this clinical study are to first learn more about safety and dosing of the study drug GS-4321 in healthy participants. The study will then learn about the safety and effectiveness of GS-4321 in participants with chronic hepatitis delta (CHD).
The primary objective of Phase 1 of this study is to evaluate the safety, tolerability and Pharmacokinetics (PK) of the escalating single doses of GS-4321 administered in healthy participants.
The primary objective of Phase 2 of this study is to evaluate the efficacy and safety of the multiple escalating doses of GS-4321 in participants with CHD.
Eligibility
Key Inclusion Criteria:
Part A:
- Participants assigned male or female at birth who are of childbearing potential and engage in heterosexual intercourse must agree to use protocol-specified method(s) of contraception.
- Have a body mass index (BMI) of ≤ 30.0 kg/m2 at screening and at admission.
Part B:
- Participants assigned male or female at birth who are of childbearing potential and engage in heterosexual intercourse must agree to use protocol-specified method(s) of contraception.
- Chronic hepatitis delta (CHD) for ≥ 6 months prior to screening, documented by prior medical history.
- Must be receiving a commercially available entecavir, TAF, or TDF for the treatment of hepatitis B virus (HBV) infection at or prior to enrollment. Coformulation as part of a fixed-dose combination for the treatment of HIV is permitted.
- Non-cirrhotic or compensated cirrhosis.
- Hepatitis delta virus ribonucleic acid (HDV RNA ) > 100 IU/mL at screening.
- Alanine aminotransferase (ALT) level > 1 × Upper limit of normal (ULN), but < 10 × ULN at screening.
Key Exclusion Criteria:
Part A:
- Positive serum or urine pregnancy test.
- Participants with plans to breastfeed during the study period.
Part B:
- Positive serum or urine pregnancy test.
- Participants with plans to breastfeed during the study period.
- Current or previous clinically decompensated liver disease, including coagulopathy, hepatic encephalopathy, and esophageal varices hemorrhage due to HDV or HBV.
- Child-Turcotte-Pugh (CTP)-B or -C or a CTP score of ≥ 7.
Note: Other protocol defined Inclusion/Exclusion criteria may apply.