A Study to Evaluate the Safety, Tolerability and Pharmacokinetics and Pharmacodynamics of RO7062931in Healthy Volunteers and Subjects With Chronic Hepatitis B

Inclusion Criteria

FOR HEALTHY VOLUNTEERS ONLY - PART 1 -

• A Body Mass Index (BMI) between 18 to 30 kg/m2 inclusive and a body weight of at least 50 kg.
• Women should be of non-childbearing potential. A woman is considered to be of childbearing potential if she is post-menarcheal but has not reached a post-menopausal state and has not undergone surgical sterilization (removal of ovaries and/or uterus).
• Men must agree to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures during treatment and up to 105 days after the last dose, and agree to refrain from donating sperm.
• Non-smoker (nor tobacco containing products) for at least 90 days prior to dosing on Day 1 and agree to remain as non-smoker during the study.

FOR CHB PARTICIPANTS ONLY - PARTS 2a and 2b:

• A BMI between 18 to 32 kg/m2 inclusive.
• Chronic hepatitis B (HBV) infection.
• Positive test for HBsAg for more than 6 months prior to randomization and HBsAg titer ≥ 10^3 IU/mL at screening.
• On entecavir, tenofovir, adefovir or telbivudine treatment for at least 6 months prior to randomization and will remain on stable treatment during the study.
• HBV deoxyribonucleic acid (DNA) ≤ 90 IU/mL for at least the preceding 6 months.
• Screening laboratory values (hematology, chemistry, urinalysis) obtained up to 56 days prior to first study treatment within normal ranges.
• Liver biopsy, fibroscan® or equivalent test obtained within the past 6 months demonstrating liver disease consistent with chronic HBV infection without evidence of bridging fibrosis or cirrhosis
• Women should be of non-childbearing potential. A woman is considered to be of childbearing potential if she is post-menarcheal but has not reached a post-menopausal state and has not undergone surgical sterilization (removal of ovaries and/or uterus).
• Men must agree to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures during treatment and up to 105 days after the last dose, and agree to refrain from donating sperm.

FOR CHB PARTICIPANTS ONLY - PART 2c

• BMI between 18 to 32 kg/m2 inclusive
• CHB infection (HBsAg-positive for at least 6 months)
• For NUC-suppressed CHB participants: Must have been treated with a single NUC for at least 12 months, and have been on the same NUC therapy for at least 3 months prior to screening; HBV DNA 30 days prior to screening); alanine aminotransferase (ALT) 6 months prior to screening and confirmed at screening; total bilirubin within normal range at screening, except for patients with Gilbert's syndrome
• For treatment-naive and immune-active participants: HBV DNA at screening >/=2x10^4 IU/mL for HBeAg positive participants, or >/=2x10^3 IU/mL for HBeAg negative participants; elevated serum ALT>2 ULN to ULN (except for participants with Gilbert's disease); international normalized ratio (INR) > 1.1 ULN; serum albumin 13 ng/mL; positive results for anti-mitochondrial antibodies (AMA > 1:80), anti-nuclear antibody (ANA > 1:80), anti-smooth muscle antibody (ASMA > 1:40), anti-thyroperoxidase antibodies (a-TPO), anti-thyroglobulin, or anti-platelet antibodies; thyroid stimulating hormone (TSH) outside of normal range; platelet count ULN or calculated creatinine clearance < 70 mL/min
• Donation or loss of blood over 500 mL within 3 months prior to randomization
• Administration of any blood product within 3 months prior to randomization
• History of alcohol abuse and/or drug abuse