Study of GS-4321 in Healthy Participants and Participants With Chronic Hepatitis Delta Virus

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.