Study To Evaluate Safety and Efficacy of Vesatolimod for the Treatment of Chronic Hepatitis B Virus in Virally-Suppressed Participants

Key Inclusion Criteria: * Must have the ability to understand and sign a written informed consent form; consent must be obtained prior to initiation of study procedures * Documented evidence of CHB infection (eg, hepatitis B surface antigen \[HBsAg\] positive for more than 6 months) with detectable HBsAg levels at screening * Have been on approved HBV OAV treatment for ≥ 1 year prior to screening, with HBV DNA below lower limit of quantitation (LLOQ), measured at least once, 6 or more months prior to screening, and HBV DNA \< 20 IU/mL at screening * Currently taking an approved HBV OAV (tenofovir, entecavir, adefovir, lamivudine, or telbivudine, either as single agents or in combination) with no change in regimen for 3 months prior to screening * Willing to provide blood sample for toll-like receptor 7 (TLR-7) and interleukin 28 B (IL28B) single-nucleotide polymorphism (SNP) assessment * Must be willing and able to comply with all study requirements Key Exclusion Criteria: * Extensive bridging fibrosis or cirrhosis * Laboratory parameters not within defined thresholds for neutropenia, anemia, thrombocytopenia, leukopenia, or other evidence of inadequate liver function * Coinfection with hepatitis C virus (HCV), HIV, or hepatitis D virus (HDV) * Evidence of hepatocellular carcinoma * Malignancy within 5 years prior to screening, with the exception of specific cancers that are cured by surgical resection (basal cell skin cancer, etc.). Participants under evaluation for possible malignancy are not eligible. * Significant cardiovascular, pulmonary, or neurological disease * Any of the following conditions that may worsen in response to interferon (IFN): * Autoimmune disease (eg, lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, sarcoidosis, moderate or severe psoriasis) * Poorly controlled diabetes mellitus * Significant psychiatric disorders * Thyroid disorder (unless controlled under treatment) * Significant pulmonary diseases (eg, chronic obstructive pulmonary disease) * Retinal disease * Immunodeficiency disorders * Received solid organ or bone marrow transplant * Received prolonged therapy with immunomodulators (eg, corticosteroids) or biologics (eg, monoclonal Ab, interferon) within 3 months of screening * Use of another investigational agents within 3 months of screening * Current alcohol or substance abuse judged by the investigator to potentially interfere with compliance * Females who are pregnant or may wish to become pregnant during the study Note: Other protocol defined Inclusion/Exclusion criteria may apply.