A Study to Investigate Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of RO7565020 in Healthy Participants and in Participants With Chronic Hepatitis B Virus Infection

Inclusion Criteria:

Healthy volunteers:

1. Healthy participants
2. Body mass index (BMI) between 18 and 32 kg/m^2

CHB participants:

1. CHB infection (HBsAg-positive for >/= 6 months)
2. On NUC (ETV, TAF, or TDF) monotherapy for >/= 12 months
3. Liver biopsy, FibroScan, or equivalent test within the past 6 months demonstrating liver disease consistent with chronic HBV infection without evidence of bridging fibrosis or cirrhosis
4. BMI between 18 and 32 kg/m^2

Exclusion Criteria:

Healthy volunteers:

1. History of any clinically significant disease
2. Concomitant disease that could interfere with treatment or conduct of study
3. Use of any treatment within the 2 weeks or within 5 half-lives prior to first dosing (whichever is longer)

CHB participants:

1. Evidence of liver cirrhosis or decompensated liver disease
2. History or suspicion of hepatocellular carcinoma (HCC)
3. History or evidence of a medical condition associated with chronic liver disease other than HBV infection, or clinically significant and not adequately controlled non-hepatic disease
4. History of or currently receiving any systemic anti-neoplastic or immune-modulatory treatment within the 8 weeks prior to the first dosing or the expectation that such treatment will be needed at any time during the study.