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

NCT05770895 | Completed Phase 1 Results

• 1 other identifier: GS-US-642-5670
• Study Type: interventional
• Target: 83
• Locations: 2 countries
• Sites: 9

Brief Summary

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

Conditions

Chronic Hepatitis B

Outcome Measures

Primary Outcomes (2)

• Percentage of Participants With Treatment-emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)

  Treatment-emergent adverse events (TEAEs) were defined as any AE with a start date on or after the study drug start date; or any AE that led to premature discontinuation of study drug. An SAE is defined as an event that, at any dose, results in the following: Death, a life-threatening situation, inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability/incapacity, a congenital anomaly/birth defect, or a medically important event or reaction.

  First dose date to end of study (followed up to 24 weeks post last dose (up to Day 225 [cohorts 1, 2], Day 253 [cohorts 3, 4, 5, 6], and Day 309 [cohorts 7 and 8])

• Percentage of Participants With Treatment-Emergent Laboratory Abnormalities

  Treatment-emergent laboratory abnormalities were defined as values that increased at least 1 toxicity grade from baseline at any time postbaseline. If the relevant baseline laboratory value is missing, any abnormality of at least Grade 1 observed postbaseline will be considered treatment emergent.

  First dose date to end of study (followed up to 24 weeks post last dose (up to Day 225 [cohorts 1, 2], Day 253 [cohorts 3, 4, 5, 6], and Day 309 [cohorts 7 and 8])

Secondary Outcomes (2)

• Percentage of Participants With ≥ 3-Fold Increase in Vaccine-Induced Hepatitis B Virus (HBV) Specific T-Cell Responses

  Up to 24 weeks post last dose (up to Day 225 [cohorts 1, 2]) or up to 12 weeks post last dose (up to Day 169 [cohorts 3, 4, 5, 6]; Day 225 [cohorts 7 and 8])

• Mean Peak Levels of Vaccine-Induced HBV Specific T-Cell Responses

  Up to 24 weeks post last dose (up to Day 225 [cohorts 1, 2]) or up to 12 weeks post last dose (up to Day 169 [cohorts 3, 4, 5, 6]; Day 225 [cohorts 7 and 8])

Study Arms (8)

Phase 1a : Cohort 1 (Healthy Participants) : GS-2829 Low Dose (2 injections)

EXPERIMENTAL

Healthy participants will receive a single low dose of GS-2829 (≥ 0.5 x 10\^6 focus-forming unit (FFU)/mL) or placebo as intramuscular (IM) injection on Days 1 and 57.

Biological: GS-2829; Biological: Placebo

Phase 1a : Cohort 2 (Healthy Participants) : GS-6779 Low Dose (2 injections)

EXPERIMENTAL

Healthy participants will receive a single low dose of GS-6779 (≥ 0.5 x 10\^6 FFU/mL) or placebo as IM injection on Days 1 and 57.

Biological: GS-6779; Biological: Placebo

Phase 1a : Cohort 3 (Healthy Participants) : GS-2829 and GS-6779 Low Dose (2 cycles)

EXPERIMENTAL

Healthy participants will receive a single low dose of GS-2829 (≥ 0.5 x 10\^6 FFU/mL) or placebo as IM injection on Days 1 and 57; and a single low dose of GS-6779 (≥ 0.5 x 10\^6 FFU/mL) or placebo as IM injection, on Days 29 and 85.

Biological: GS-2829; Biological: GS-6779; Biological: Placebo

Phase 1a : Cohort 4 (Healthy Participants) : GS-2829 and GS-6779 High Dose (2 cycles)

EXPERIMENTAL

Healthy participants will receive a single high dose of GS-2829 (≥ 0.5 x 10\^7 FFU/mL) or placebo as IM injection, on Days 1 and 57; and a single high dose of GS-6779 (≥ 0.5 x 10\^7 FFU/mL) or placebo as IM injection, on Days 29 and 85.

Biological: GS-2829; Biological: GS-6779; Biological: Placebo

Phase 1a : Cohort 8 (Healthy Participants) : GS-2829 and GS-6779 High Dose (3 cycles)

EXPERIMENTAL

Healthy participants will receive a single high dose of GS-2829 (≥ 0.5 x 10\^7 FFU/mL) or placebo as IM injection on Days 1, 57 and 113; and a single high dose of GS-6779 (≥ 0.5 x 10\^7 FFU/mL) or placebo as IM injection on Days 29, 85 and 141.

Biological: GS-2829; Biological: GS-6779; Biological: Placebo

Phase 1b : Cohort 5 (VS Participants with CHB) : GS-2829 and GS-6779 Low Dose (2 cycles)

EXPERIMENTAL

Virally suppressed (VS) participants with Chronic Hepatitis B (CHB) will receive a single low dose of GS-2829 (≥ 0.5 x 10\^6 FFU/mL) or placebo as IM injection on Days 1 and 57; and a single low dose of GS-6779 (≥ 0.5 x 10\^6 FFU/mL) or placebo as IM injection on Days 29 and 85.

Biological: GS-2829; Biological: GS-6779; Biological: Placebo

Phase 1b : Cohort 6 (VS Participants with CHB) : GS-2829 and GS-6779 High Dose (2 cycles)

EXPERIMENTAL

VS participants with CHB will receive a single high dose of GS-2829 (≥ 0.5 x 10\^7 FFU/mL) or placebo as IM injection on Days 1 and 57; and a single high dose of GS-6779 (≥ 0.5 x 10\^7 FFU/mL) or placebo as IM injection on Days 29 and 85.

Biological: GS-2829; Biological: GS-6779; Biological: Placebo

Phase 1b : Cohort 7 (VS Participants with CHB) : GS-2829 and GS-6779 High Dose (3 cycles)

EXPERIMENTAL

VS participants with CHB will receive a single high dose of GS-2829 (≥ 0.5 x 10\^7 FFU/mL) or placebo as IM injection on Days 1, 57 and 113; and a single high dose of GS-6779 (≥ 0.5 x 10\^7 FFU/mL) or placebo as IM injection on Days 29, 85 and 141.

Biological: GS-2829; Biological: GS-6779; Biological: Placebo

Interventions

GS-2829 BIOLOGICAL

Administered intramuscularly

Phase 1a : Cohort 1 (Healthy Participants) : GS-2829 Low Dose (2 injections); Phase 1a : Cohort 3 (Healthy Participants) : GS-2829 and GS-6779 Low Dose (2 cycles); Phase 1a : Cohort 4 (Healthy Participants) : GS-2829 and GS-6779 High Dose (2 cycles); Phase 1a : Cohort 8 (Healthy Participants) : GS-2829 and GS-6779 High Dose (3 cycles); Phase 1b : Cohort 5 (VS Participants with CHB) : GS-2829 and GS-6779 Low Dose (2 cycles); Phase 1b : Cohort 6 (VS Participants with CHB) : GS-2829 and GS-6779 High Dose (2 cycles); Phase 1b : Cohort 7 (VS Participants with CHB) : GS-2829 and GS-6779 High Dose (3 cycles)

GS-6779 BIOLOGICAL

Administered intramuscularly

Phase 1a : Cohort 2 (Healthy Participants) : GS-6779 Low Dose (2 injections); Phase 1a : Cohort 3 (Healthy Participants) : GS-2829 and GS-6779 Low Dose (2 cycles); Phase 1a : Cohort 4 (Healthy Participants) : GS-2829 and GS-6779 High Dose (2 cycles); Phase 1a : Cohort 8 (Healthy Participants) : GS-2829 and GS-6779 High Dose (3 cycles); Phase 1b : Cohort 5 (VS Participants with CHB) : GS-2829 and GS-6779 Low Dose (2 cycles); Phase 1b : Cohort 6 (VS Participants with CHB) : GS-2829 and GS-6779 High Dose (2 cycles); Phase 1b : Cohort 7 (VS Participants with CHB) : GS-2829 and GS-6779 High Dose (3 cycles)

Placebo BIOLOGICAL

Administered intramuscularly

Phase 1a : Cohort 1 (Healthy Participants) : GS-2829 Low Dose (2 injections); Phase 1a : Cohort 2 (Healthy Participants) : GS-6779 Low Dose (2 injections); Phase 1a : Cohort 3 (Healthy Participants) : GS-2829 and GS-6779 Low Dose (2 cycles); Phase 1a : Cohort 4 (Healthy Participants) : GS-2829 and GS-6779 High Dose (2 cycles); Phase 1a : Cohort 8 (Healthy Participants) : GS-2829 and GS-6779 High Dose (3 cycles); Phase 1b : Cohort 5 (VS Participants with CHB) : GS-2829 and GS-6779 Low Dose (2 cycles); Phase 1b : Cohort 6 (VS Participants with CHB) : GS-2829 and GS-6779 High Dose (2 cycles); Phase 1b : Cohort 7 (VS Participants with CHB) : GS-2829 and GS-6779 High Dose (3 cycles)

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Gilead Sciences: lead

Study Sites (9)

New Zealand Clinical Research (NZCR)

Auckland, 1010, New Zealand

Location

Chia-Yi Christian Hospital

Chiayi City, 60002, Taiwan

Location

St. Martin De Porres Hospital

Chiayi City, 600, Taiwan

Location

Kaohsiung Medical University Hospital

Kaohsiung City, 807, Taiwan

Location

E-DA Hospital

Kaohsiung City, 82445, Taiwan

Location

Chang Gung Medical Foundation Kaohsiung Chang Gung Memorial Hospital

Kaohsiung City, 833, Taiwan

Location

National Cheng Kung University Hospital

Tainan, 7428, Taiwan

Location

National Taiwan University Hospital

Taipei, 100229, Taiwan

Location

Chang Gung Medical Foundation Linkou Chang Gung Memorial Hospital

Taoyuan, 33305, Taiwan

Location

Related Publications (2)

• Gane E J et al. Safety, tolerability and immunogenicity of GS-2829 and GS-6779, a novel arenaviral vectored therapeutic hepatitis B vaccine: results from a phase 1a study in healthy participants. Poster THU-246. Presented at European Association for the Study of the Liver (EASL), 07-10 May 2025, Amsterdam, The Netherlands. J Hepatol 2025;82(S1):S831.

  BACKGROUND

• Gane E J, et al. Safety, tolerability, immunogenicity, and antiviral efficacy of GS-2829 and GS-6779, a novel, arenaviral-vectored, therapeutic hepatitis B vaccine: Results from a phase 1b study in virally suppressed patients with chronic hepatitis B. *Hepatology*. 2025;72(Suppl 1):197. Presented at: AASLD The Liver Meeting; November 7-11, 2025; San Diego, CA.

  BACKGROUND

Related Links

• Gilead Clinical Trials Website

MeSH Terms

Conditions

Hepatitis B, Chronic

Condition Hierarchy (Ancestors)

Hepatitis B; Blood-Borne Infections; Communicable Diseases; Infections; Hepadnaviridae Infections; DNA Virus Infections; Virus Diseases; Hepatitis, Viral, Human; Hepatitis, Chronic; Hepatitis; Liver Diseases; Digestive System Diseases; Chronic Disease; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Results Point of Contact

• Title: Gilead Clinical Study Information Center
• Organization: Gilead Sciences

GileadClinicalTrials@gilead.com

1-833-445-3230 (GILEAD-0)

Study Officials

• Gilead Study Director

  Gilead Sciences

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: OTHER
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 1, 2023
• First Posted: March 16, 2023
• Study Start: April 3, 2023
• Primary Completion: January 15, 2025
• Study Completion: January 15, 2025
• Last Updated: January 23, 2026
• Results First Posted: January 23, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

TW (8); NZ (1)