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Study of GS-4321 for Chronic Hepatitis Delta

This study is testing a drug called GS-4321 for chronic hepatitis delta (CHD). First, it will look at the safety and how the body handles GS-4321 in healthy volunteers. Then, it will study the safety and how well GS-4321 works in people with CHD. The drug will be given either under the skin (subcutaneous) or into a vein (intravenously). Researchers will be watching for any side effects, serious side effects, and abnormal lab results to understand the safety of GS-4321. You may be able to join if you are between 18 and 69 years old and meet other health requirements, including a body mass index (BMI) of 30.0 kg/m2 or less. The study aims to enroll about 200 participants.

Study design
This interventional study will involve about 200 participants, including healthy volunteers and those with chronic hepatitis delta. It will test different doses of GS-4321.
What's involved
Participants will receive GS-4321 or a placebo. Safety will be monitored for up to 44 weeks in healthy participants and up to 96 weeks in those with chronic hepatitis delta.
Compensation
Not stated in the trial record.
Follow-up
Participants with chronic hepatitis delta will have a post-treatment follow-up period of 48 weeks after their last dose.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT07096193

Study of GS-4321 in Healthy Participants and Participants With Chronic Hepatitis Delta Virus

Recruiting
PHASE1Ages 18–69InterventionalTreatment
Gilead Sciences
~200 participants
Updated 2026-08-27 on ClinicalTrials.gov
What's tested:GS-4321GS-4321 Placebo

At a glance

Recruiting sites
28 of 28 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Phase 1 and 2: Percentage of Participants With Treatment-emergent Adverse Events
Measured over Phase 1: First dose up to 44 weeks; Phase 2: First dose up to 96 Weeks plus 48 weeks of posttreatment follow-up
+7 more outcomes measured

Conditions

Chronic Hepatitis Delta

Explore related trials

Chronic hepatitis EHealthy VolunteersHDV RNA

Where it's being run

28 sites across 12 states
Turkey (Türkiye)6
Romania4
South Korea4
Taiwan4
California2
Moldova2
Kentucky1
Maryland1

Study leadership

  • Gilead Study Director · STUDY_DIRECTOR · Gilead Sciences

Who to contact

Gilead Clinical Study Information Center
[email protected]
1-833-445-3230 (GILEAD-0)
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

Participants assigned male or female at birth who are of childbearing potential and engage in heterosexual intercourse must agree to use protocol-specified method(s) of contraception.
Have a body mass index (BMI) of ≤ 30.0 kg/m2 at screening and at admission.
Participants assigned male or female at birth who are of childbearing potential and engage in heterosexual intercourse must agree to use protocol-specified method(s) of contraception.
Chronic hepatitis delta (CHD) for ≥ 6 months prior to screening, documented by prior medical history.
Must be receiving a commercially available entecavir, TAF, or TDF for the treatment of hepatitis B virus (HBV) infection at or prior to enrollment. Coformulation as part of a fixed-dose combination for the treatment of HIV is permitted.
Non-cirrhotic or compensated cirrhosis.
Hepatitis delta virus ribonucleic acid (HDV RNA ) \> 500 IU/mL at screening.
Alanine aminotransferase (ALT) level \> 1 × Upper limit of normal (ULN), but \< 10 × ULN at screening.

Exclusion

Positive serum or urine pregnancy test.
Participants with plans to breastfeed during the study period.
Positive serum or urine pregnancy test.
Participants with plans to breastfeed during the study period.
Current or previous clinically decompensated liver disease, including coagulopathy, hepatic encephalopathy, and esophageal varices hemorrhage due to HDV or HBV.
Child-Turcotte-Pugh (CTP)-B or -C or a CTP score of ≥ 7.

What this trial measures

  • Phase 1 and 2: Percentage of Participants With Treatment-emergent Adverse EventsPhase 1: First dose up to 44 weeks; Phase 2: First dose up to 96 Weeks plus 48 weeks of posttreatment follow-up
  • Phase 1 and 2: Percentage of Participants With Treatment-emergent Serious Adverse EventsPhase 1: First dose up to 44 weeks; Phase 2: First dose up to 96 Weeks plus 48 weeks of posttreatment follow-up
  • Phase 1 and 2: Percentage of Participants Experiencing Treatment-emergent Clinical Laboratory AbnormalitiesPhase 1: First dose up to 44 weeks; Phase 2: First dose up to 96 Weeks plus 48 weeks of posttreatment follow-up
  • Phase 1: Serum Pharmacokinetic (PK) parameter; AUC of GS-4321First dose up to 24 Weeks

    AUC is defined as the area under the concentration versus time curve

  • Phase 1: Serum PK Parameter: CmaxFirst dose up to 24 Weeks

    Cmax is defined as the maximum observed concentration of drug.

  • Phase 1: Serum PK Parameter: TmaxFirst dose up to 24 Weeks

    Tmax is defined as the time (observed time point) of Cmax.

  • Phase 1: Serum PK Parameter: t1/2First dose up to 24 Weeks
  • Phase 2: Proportion of Participants with Combined ResponseUp to 96 Weeks

    Combined Response is defined as undetectable hepatitis delta virus (HDV) RNA or ≥ 2 log10 decrease in HDV RNA from baseline and normal alanine aminotransferase (ALT) normalization (ALT \< upper limit of normal (ULN) at week 24).