Safety, Tolerability and Antiviral Activity of GS-9688 in Virally-Suppressed Adults With Chronic Hepatitis B

Key Inclusion Criteria:

- Must have the ability to understand and sign a written informed consent form, which
must be obtained prior to initiation of study procedures

- Adult males and non-pregnant, non-lactating females

- Documented evidence of chronic HBV infection with detectable HBsAg levels

- On commercially available HBV OAV treatment(s) for at least 6 months with no change in
regimen for 3 months prior to screening

- HBV Deoxyribonucleic acid (DNA) ≤ 20 IU/mL for 6 or more months prior to screening

- Screening Electrocardiogram (ECG) without clinically significant abnormalities

Key Exclusion Criteria:

- Extensive bridging fibrosis or cirrhosis

- Adults meeting any of the protocol defined exclusionary laboratory parameters at
screening:

- Alanine aminotransferase (ALT) >3x Upper Limit of Normal (ULN)

- International normalized ratio (INR) > ULN unless the adult is stable on an
anticoagulant regimen

- Albumin < 3.5 g/dL

- Direct bilirubin >1.5x ULN

- Platelet Count < 100,000/uL

- Estimated creatinine clearance < 60 mL/min (using the Cockcroft-Gault method)

- Co-infection with human immunodeficiency virus, hepatitis C virus or hepatitis D virus

- Prior history of hepatocellular carcinoma (HCC) or screening alpha-fetoprotein ≥ 50
ng/mL without imaging

- Diagnosis of autoimmune disease, poorly controlled diabetes mellitus, significant
psychiatric illness, severe chronic obstructive pulmonary disease, hemoglobinopathy,
retinal disease, or are immunosuppressed.

- Chronic liver disease of a non-HBV etiology, except for non-alcoholic fatty liver
disease

- Received solid organ or bone marrow transplant

- Received prolonged therapy with immunomodulators or biologics within 3 months of
screening

- Use of another investigational agent within 90 days of screening, unless allowed by
the Sponsor

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