Study of HBV Therapeutic Vaccines GS-2829 and GS-6779 in Healthy Participants and Participants With Chronic Hepatitis B

A Phase 1a/1b Study to Evaluate the Safety and Tolerability of Repeated Doses of Nonreplicating Arenavirus Vector Therapeutic Vaccines GS-2829 and GS-6779 in Healthy Participants and Participants With Chronic Hepatitis B (CHB)

The goal of this clinical study is to learn more about GS-2829 and GS-6779 in healthy participants and participants with CHB.

Key Inclusion Criteria:

Phase 1a and 1b:

• Body mass index (BMI) of ≤ 32.0 kg/m^2.
• Non-diabetic without impaired glucose tolerance.
• No evidence of cardiac disease based on 12 lead electrocardiogram (ECG).

Phase 1a (Healthy Individuals) only:

• Aged 18 through 60 years.
• No prior history of Hepatitis B infection with a negative hepatitis B surface antigen (HBsAg) and Hepatitis B (HBV) core antibody.

Phase 1b (Virally Suppressed chronic hepatitis B (CHB) Individuals)):

• Aged 18 through 65 years.
• Documented CHB and HBsAg ≤ 5000 IU/mL at screening.
• No evidence of advanced fibrosis by Fibroscan (defined as Fibroscan < 9 kilo pascal (kPa) within 6 months of screening).
• Diagnosed with CHB on suppressive oral antiviral for ≥ 6 months.
• Must have received an approved HBV-active oral antiviral agent for ≥ 6 months prior to screening with HBV DNA below lower limit of quantification (LLOQ) for ≥ 3 months prior to screening and with no plan to stop HBV-active antivirals during the study.

Key Exclusion Criteria:

Phase 1a and 1b:

• Use of any systemic antibiotics within 30 days of screening.
• Receipt of any HBV vaccine within 12 months of screening visit or planning HBV vaccination during the study period.
• Receipt of any investigational product within 3 months or vaccine within 3 months of screening (with the exception of influenza and severe acute respiratory syndrome (SARs) coronavirus (COV) - 2 (SARS-CoV-2) vaccines, which if needed, should be administered at least 14 days before or after an investigational product administration).
• Receipt of immunoglobulin or other blood products within 3 months of screening.
• Positive serum pregnancy test at screening or positive urine pregnancy on Day 1.
• Have been treated with systemic steroids, immunosuppressant therapies, or chemotherapeutic agents within 3 months prior to screening or is expected to receive these agents during the study (eg, corticosteroids, immunoglobulins, other immune or cytokine-based therapies).
• Participation in any other clinical study (including observational studies) without prior approval from the sponsor is prohibited while participating in the study.

Note - Other protocol defined Inclusion/Exclusion criteria may apply.