Chronic Hepatitis BPhase 1NCT05770895

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

A Phase 1 study testing GS-2829 and GS-6779 in people with Chronic Hepatitis B, run by Gilead Sciences at 9 sites in 2 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

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

Who is it for?: Ages 18 to 65 yearsHealthy volunteers can take part
Conditions the study is for: Chronic Hepatitis B
What is being tested?: GS-2829 and GS-6779
Type of treatment: Injection or infusion
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 83 participants
Where: 9 sitesin 2 countries
Study dates: 3 Apr 2023to 15 Jan 2025
Phase: Phase 1
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 to 65 years
All sexes
Healthy volunteers accepted
Adult, Older adult

Who may be able to join

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.

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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.

Who cannot join

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.

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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.

Trial locations and contacts

9 sites in 2 countries.

Country

City, postcode or hospital

9 sites in 2 countries

Taiwan8 sites

Chia-Yi Christian Hospital
Chiayi City, 60002
St. Martin De Porres Hospital
Chiayi City, 600
Kaohsiung Medical University Hospital
Kaohsiung City, 807
E-DA Hospital
Kaohsiung City, 82445
Chang Gung Medical Foundation Kaohsiung Chang Gung Memorial Hospital
Kaohsiung City, 833
National Cheng Kung University Hospital
Tainan, 7428
National Taiwan University Hospital
Taipei, 100229
Chang Gung Medical Foundation Linkou Chang Gung Memorial Hospital
Taoyuan City, 33305

Other trials in Taiwan

New Zealand1 site

New Zealand Clinical Research (NZCR)
Auckland, 1010

Other trials in New Zealand

About this study

Official title: 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.

Conditions: Chronic Hepatitis B
Being tested: GS-2829, GS-6779, Placebo
Medical subject headings: Hepatitis B, Chronic

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

GS-2829Biological
Administered intramuscularly
GS-6779Biological
Administered intramuscularly
PlaceboBiological
Administered intramuscularly

Study groups in NCT05770895
Study group	Role	What they receive
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. Receives: 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. Receives: 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. Receives: 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. Receives: 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. Receives: 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. Receives: 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. Receives: 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. Receives: Biological: GS-2829; Biological: GS-6779; Biological: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

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.
Measured: 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.
Measured: 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
Vaccine-induced HBV-specific T cell responses were measured using an interferon-gamma (IFN-γ), enzyme-linked immunospot (ELISpot) assay with a readout of spot forming cells (SFCs) /10^6 peripheral blood mononuclear cells (PBMCs). Total response was the sum of the dimethylsulfoxide (DMSO) -adjusted averages for the 4 HBV peptides (HBV core + HBV polymerase (pol) A + HBV pol B + HBV surface antigen (sAg)). Response was defined as a ≥ 3-fold increase over baseline in vaccine-induced HBV-specific total T cell response (measured using the IFN-γ ELISpot assay). A participant's highest fold-increase postbaseline was utilized for analysis of responder/non-responder. Participants with missing values for fold change over baseline were counted as failures (missing = failure).
Measured: 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
Vaccine-induced HBV-specific T cell responses were measured using an IFN-γ ELISpot assay with a readout of SFCs/10^6 PBMCs. Total response was the sum of the DMSO-adjusted averages for the 4 HBV peptides (HBV Core + HBV Pol A + HBV Pol B + HBV sAg). Peak values were the highest posttreatment value for an individual participant and then means were calculated across the participants in a cohort.
Measured: 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])

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

3 Apr 202315 Jan 2025

First posted16 Mar 2023
Study start3 Apr 2023
Primary completion15 Jan 2025
Study completion15 Jan 2025

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Publications (2)Papers the sponsor has linked to this study.
Other trials for Chronic Hepatitis BStudies of the same condition, open and under way.
More trials run by Gilead SciencesThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 1
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Double blind
Who is masked: Participant, Investigator
Enrolment: 83 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05770895
Sponsor's protocol ID: GS-US-642-5670
Status last verified: Jan 2026
First submitted: 1 Mar 2023
Last updated: 23 Jan 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: No

Publications

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.
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.

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

Active, not recruitingPhase 2
A Study of Sequential Therapy With Daplusiran/Tomligisiran (DAP/TOM) Followed by Bepirovirsen in Participants Living With Chronic Hepatitis B (CHB)
Chronic Hepatitis B Virus Infection, Hepatitis B
RecruitingObservational study
Evaluation of Patients With Liver Disease
Hepatitis D, Hepatitis C
Active, not recruitingPhase 2
Study of Bepirovirsen in Participants Living With Human Immunodeficiency Virus and Chronic Hepatitis B Virus Infection (B-Focus)
Hepatitis B
Active, not recruitingPhase 2
Long-term Follow-up Study to Evaluate Durability of Treatment Response in Previous Bepirovirsen Study Participants (B-Sure)
Hepatitis B
Enrolling by invitationPhase 1
A Phase I Clinical Trial of CPU-YL01 Injection in Patients With Chronic Hepatitis B.
Chronic Hepatitis B

All Chronic Hepatitis B trials

Study at a glance

From the registry record, last updated by the sponsor on 23 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: 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)
ClinicalTrials.gov ID: NCT05770895
Acronym / sponsor ID: GS-US-642-5670
Conditions: Chronic Hepatitis B
Phase: Phase 1
Study type: Interventional
Recruitment status: Completed
Enrolment: 83 participants (actual)
Lead sponsor: Gilead SciencesIndustry (pharma, biotech, devices)
Study start: 3 Apr 2023 (actual)
Primary completion: 15 Jan 2025 (actual)
Study completion: 15 Jan 2025 (actual)
First posted: 16 Mar 2023 (actual)
Results: Posted 23 Jan 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

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

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Double blind (participant, investigator)
Number of arms: 8

Arm	Type	Receives
Phase 1a : Cohort 1 (Healthy Participants) : GS-2829 Low Dose (2 injections)	Experimental	Biological: GS-2829, Biological: PlaceboHealthy 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.
Phase 1a : Cohort 2 (Healthy Participants) : GS-6779 Low Dose (2 injections)	Experimental	Biological: GS-6779, Biological: PlaceboHealthy 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.
Phase 1a : Cohort 3 (Healthy Participants) : GS-2829 and GS-6779 Low Dose (2 cycles)	Experimental	Biological: GS-2829, Biological: GS-6779, Biological: PlaceboHealthy 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.
Phase 1a : Cohort 4 (Healthy Participants) : GS-2829 and GS-6779 High Dose (2 cycles)	Experimental	Biological: GS-2829, Biological: GS-6779, Biological: PlaceboHealthy 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.
Phase 1a : Cohort 8 (Healthy Participants) : GS-2829 and GS-6779 High Dose (3 cycles)	Experimental	Biological: GS-2829, Biological: GS-6779, Biological: PlaceboHealthy 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.
Phase 1b : Cohort 5 (VS Participants with CHB) : GS-2829 and GS-6779 Low Dose (2 cycles)	Experimental	Biological: GS-2829, Biological: GS-6779, Biological: PlaceboVirally 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.
Phase 1b : Cohort 6 (VS Participants with CHB) : GS-2829 and GS-6779 High Dose (2 cycles)	Experimental	Biological: GS-2829, Biological: GS-6779, Biological: PlaceboVS 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.
Phase 1b : Cohort 7 (VS Participants with CHB) : GS-2829 and GS-6779 High Dose (3 cycles)	Experimental	Biological: GS-2829, Biological: GS-6779, Biological: PlaceboVS 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.

Who may qualify

Ages: 18 to 65 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult

Key inclusion criteria (13 listed)

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).
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.

Key exclusion criteria (9 listed)

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.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
GS-2829Administered intramuscularly	Biological	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-6779Administered intramuscularly	Biological	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)
PlaceboAdministered intramuscularly	Biological	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)

Primary outcome

Percentage of Participants With Treatment-emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time frame: 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])
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.
Percentage of Participants With Treatment-Emergent Laboratory Abnormalities
Time frame: 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])
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.

2 secondary outcomes

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

Results and safety

Results posted to the registry on 23 Jan 2026, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Phase 1a : Cohort 1 (Healthy Participants) : GS-2829 Low Dose (2 Injections)	8	8
Phase 1a : Cohort 2 (Healthy Participants) : GS-6779 Low Dose (2 Injections)	8	8
Phase 1a : Cohort 3 (Healthy Participants) : GS-2829 and GS-6779 Low Dose (2 Cycles)	10	8
Phase 1a : Cohort 4 (Healthy Participants) : GS-2829 and GS-6779 High Dose (2 Cycles)	8	8
Phase 1a : Cohort 8 (Healthy Participants) : GS-2829 and GS-6779 High Dose (3 Cycles)	9	7
Phase 1a: Placebo : Healthy Participants	10	10
Phase 1b : Cohort 5 (VS Participants With CHB) : GS-2829 and GS-6779 Low Dose (2 Cycles)	8	8
Phase 1b : Cohort 6 (VS Participants With CHB) : GS-2829 and GS-6779 High Dose (2 Cycles)	8	8
Phase 1b : Cohort 7 (VS Participants With CHB) : GS-2829 and GS-6779 High Dose (3 Cycles)	8	8
Phase 1b: Placebo : VS CHB Participants	6	6

Primary outcome: Percentage of Participants With Treatment-emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)

Time frame: 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]). Number. Unit: percentage of participants

Measure	Phase 1a : Cohort 1 (Healthy Participants) : GS-2829 Low Dose (2 Injections) n = 8	Phase 1a : Cohort 2 (Healthy Participants) : GS-6779 Low Dose (2 Injections) n = 8	Phase 1a : Cohort 3 (Healthy Participants) : GS-2829 and GS-6779 Low Dose (2 Cycles) n = 8	Phase 1a : Cohort 4 (Healthy Participants) : GS-2829 and GS-6779 High Dose (2 Cycles) n = 8	Phase 1a : Cohort 8 (Healthy Participants) : GS-2829 and GS-6779 High Dose (3 Cycles) n = 9	Phase 1a: Placebo : Healthy Participants n = 10	Phase 1b : Cohort 5 (VS Participants With CHB) : GS-2829 and GS-6779 Low Dose (2 Cycles) n = 8	Phase 1b : Cohort 6 (VS Participants With CHB) : GS-2829 and GS-6779 High Dose (2 Cycles) n = 8	Phase 1b : Cohort 7 (VS Participants With CHB) : GS-2829 and GS-6779 High Dose (3 Cycles) n = 8	Phase 1b: Placebo : VS CHB Participants n = 6
Any TEAE	100.0	100.0	100.0	100.0	100.0	90.0	75.0	62.5	75.0	50.0
SAE	0	0	0	0	11.1	0	0	0	0	0

Population analysed: Participants in the Safety Analysis Set were analyzed.

Primary outcome: Percentage of Participants With Treatment-Emergent Laboratory Abnormalities

Measure	Phase 1a : Cohort 1 (Healthy Participants) : GS-2829 Low Dose (2 Injections) n = 8	Phase 1a : Cohort 2 (Healthy Participants) : GS-6779 Low Dose (2 Injections) n = 8	Phase 1a : Cohort 3 (Healthy Participants) : GS-2829 and GS-6779 Low Dose (2 Cycles) n = 8	Phase 1a : Cohort 4 (Healthy Participants) : GS-2829 and GS-6779 High Dose (2 Cycles) n = 8	Phase 1a : Cohort 8 (Healthy Participants) : GS-2829 and GS-6779 High Dose (3 Cycles) n = 9	Phase 1a: Placebo : Healthy Participants n = 10	Phase 1b : Cohort 5 (VS Participants With CHB) : GS-2829 and GS-6779 Low Dose (2 Cycles) n = 8	Phase 1b : Cohort 6 (VS Participants With CHB) : GS-2829 and GS-6779 High Dose (2 Cycles) n = 8	Phase 1b : Cohort 7 (VS Participants With CHB) : GS-2829 and GS-6779 High Dose (3 Cycles) n = 8	Phase 1b: Placebo : VS CHB Participants n = 6
Value	100.0	87.5	100.0	100.0	88.9	90.0	87.5	100.0	100.0	100.0

Population analysed: Participants in the Safety Analysis Set were analyzed.

2 secondary outcomes are reported in the full results.

Adverse events

Time frame: Up to Day 225 for Cohorts 1, 2; Up to Day 253 for Cohorts 3, 4, 5, 6; Up to Day 309 for Cohorts 7 and 8. Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Phase 1a : Cohort 1 (Healthy Participants) : GS-2829 Low Dose (2 Injections)	0 of 8 (0%)	8 of 8 (100%)	0 of 8
Phase 1a : Cohort 2 (Healthy Participants) : GS-6779 Low Dose (2 Injections)	0 of 8 (0%)	8 of 8 (100%)	0 of 8
Phase 1a : Cohort 3 (Healthy Participants) : GS-2829 and GS-6779 Low Dose (2 Cycles)	0 of 8 (0%)	8 of 8 (100%)	0 of 10
Phase 1a : Cohort 4 (Healthy Participants) : GS-2829 and GS-6779 High Dose (2 Cycles)	0 of 8 (0%)	8 of 8 (100%)	0 of 8
Phase 1a : Cohort 8 (Healthy Participants) : GS-2829 and GS-6779 High Dose (3 Cycles)	1 of 9 (11.1%)	9 of 9 (100%)	0 of 9
Phase 1a: Placebo : Healthy Participants	0 of 10 (0%)	9 of 10 (90%)	0 of 10
Phase 1b : Cohort 5 (VS Participants With CHB) : GS-2829 and GS-6779 Low Dose (2 Cycles)	0 of 8 (0%)	6 of 8 (75%)	0 of 8
Phase 1b : Cohort 6 (VS Participants With CHB) : GS-2829 and GS-6779 High Dose (2 Cycles)	0 of 8 (0%)	5 of 8 (62.5%)	0 of 8
Phase 1b : Cohort 7 (VS Participants With CHB) : GS-2829 and GS-6779 High Dose (3 Cycles)	0 of 8 (0%)	6 of 8 (75%)	0 of 8
Phase 1b: Placebo : VS CHB Participants	0 of 6 (0%)	3 of 6 (50%)	0 of 6

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 23 Jan 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
BackgroundGane 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.
BackgroundGane 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.
Gilead Clinical Trials WebsiteLink provided by the sponsor.
Individual participant dataSharing planned: No

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Gilead Study Director study director

Gilead Sciences

9 sites in 2 countries: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing GS-2829 and GS-6779 in people with Chronic Hepatitis B, run by Gilead Sciences at 9 sites in 2 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 13 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 23 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 9 sites in Taiwan, New Zealand. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 23 Jan 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Percentage of Participants With Treatment-emergent Adverse Events (AEs) and Serious Adverse Events (SAEs) (time frame: 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])). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05770895, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Jan 2026.