Study to Compare GS-1179 Versus Valacyclovir in HSV-2 Seropositive Participants With Recurrent Genital Herpes

October 28, 2026 updated by: Gilead Sciences

A Phase 2b, Randomized, Double-Blind, Active-Control, Parallel-Group Study to Evaluate the Safety and Efficacy of GS-1179 Versus Valacyclovir in HSV-2 Seropositive Participants With Recurrent Genital Herpes

The goal of this clinical study is to compare the study drug GS-1179, versus valacyclovir (VACV) in herpes simplex virus type 2 (HSV-2) seropositive participants with recurrent genital herpes.

The primary objective of this study are to evaluate the safety and tolerability of GS-1179 versus VACV and to evaluate the antiviral effect of GS-1179 versus VACV.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

300

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Key Inclusion Criteria:

  • Individuals assigned male or female at birth, 18 years of age or older at screening, able to understand and give written informed consent and comply with treatment and follow up. Individuals assigned male or female at birth who are of childbearing potential and engage in heterosexual intercourse must be nonpregnant, nonlactating, and agree to use protocol-specified method(s) of contraception.
  • Individual is HSV-2 seropositive (or HSV-1 seropositive AND HSV-2 seropositive)
  • Individual has a history of recurrent genital herpes for at least 1 year, with 4 to 9 clinical occurrences in the last year or, if currently on suppressive therapy, 4 to 9 occurrences a year prior to initiating suppressive therapy.
  • Other than HSV infection, individual is in good health (as determined by the investigator). Medical history and physical examination should be without clinically significant abnormalities.

Key Exclusion Criteria:

  • Individual has an acute episode of genital herpes during screening or on Day 1 prior to dosing.
  • Individual has any other clinically significant medical, behavioral, mental condition, substance use disorder, or pharmacologic or surgical treatment that, in the opinion of the investigator or the sponsor, may interfere with efficacy or safety assessments, or the absorption, distribution, and/or elimination of the study drug, or make the individual unsuitable for study participation.
  • Individual has a history of refractory or resistant HSV infection to any HSV-specific nucleoside analog including valacyclovir, acyclovir, famciclovir, penciclovir, ganciclovir, or valganciclovir.
  • Individual has had treatment with any investigational or approved helicase-primase inhibitor (HPI) (including ABI-5366, ABI-1179, pritelivir, adibelivir [IM-250], amenamavir) or received an investigational HSV vaccine. However, individuals may be eligible if they participated in an investigational HPI study or an investigational HSV vaccine study but have sponsor documentation that they did not receive active product (eg, placebo recipients).

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: GS-1179 High Dose + VACV Placebo to Match (PTM)

Participants will be randomized to receive a high-dose of GS-1179 once weekly up to 85 days and VACV PTM once daily up to 92 days.
Drug: GS-1179

Administered orally

Drug: Valacyclovir PTM

Administered orally
Experimental: GS-1179 Low Dose + VACV Placebo to Match (PTM)

Participants will be randomized to receive a low-dose of GS-1179 once weekly up to 85 days and VACV PTM once daily up to 92 days.
Drug: GS-1179

Administered orally

Drug: Valacyclovir PTM

Administered orally
Active Comparator: VACV + GS-1179 PTM

Participants will be randomized to receive VACV once daily up to 92 days and GS-1179 PTM once weekly up to 85 days.
Drug: GS-1179 PTM

Administered orally

Drug: Valacyclovir

Administered orally

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Percentage of Participants Experiencing Adverse Events (AEs)
Time Frame: Enrollment up to 92 days
Enrollment up to 92 days
Percentage of Participants Experiencing Premature Study-Dug Discontinuation due to AEs
Time Frame: Enrollment up to 92 days
Enrollment up to 92 days
Percentage of Participants Experiencing Treatment-Emergent Laboratory Abnormalities
Time Frame: First dose date up to 92 days
First dose date up to 92 days
Herpes Simplex Virus Type 2 (HSV-2) Shedding Rate During the Swabbing Period
Time Frame: Day 8 to Day 38
Day 8 to Day 38

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Proportion of Participants Free of Genital Herpes Recurrences at Day 92
Time Frame: Day 92
Day 92
Proportion of Participants Free of Genital Herpes Recurrences at Day 120
Time Frame: Day 120
Day 120
Genital Herpes Lesion Rate During the Treatment Period
Time Frame: Up to 92 days
Up to 92 days
Genital Herpes Lesion Duration During the Treatment Period
Time Frame: Up to 92 days
Up to 92 days
Virologically Confirmed Genital Herpes Lesion Rate During the Treatment Period
Time Frame: Up to 92 days
Up to 92 days
Virologically Confirmed Genital Herpes Lesion Duration During the Treatment Period
Time Frame: Up to 92 days
Up to 92 days
Time to Suppression of HSV-2 Shedding
Time Frame: Up to 92 days
Up to 92 days
Number of HSV-2 Shedding Episodes During the Swabbing Period
Time Frame: Day 8 to Day 38
Day 8 to Day 38
Duration of HSV-2 Shedding Episodes During the Swabbing Period
Time Frame: Day 8 to Day 38
Day 8 to Day 38
Proportion of Participants With Subclinical HSV-2 Shedding During the Swabbing Period
Time Frame: Day 8 to Day 38

Subclinical HSV-2 shedding is defined as swabs testing positive for HSV-2 DNA during the Swabbing Period that are not accompanied by lesions.
Day 8 to Day 38
HSV-2 DNA (Copies/mL) for Swab Samples that are Positive for HSV-2 DNA During the Swabbing Period
Time Frame: Day 8 to Day 38
Day 8 to Day 38
HSV-2 DNA (Copies/mL) for Positive Swab Samples in the Absence of Lesions (Subclinical Shedding) During the Swabbing Period
Time Frame: Day 8 to Day 38
Day 8 to Day 38
Proportion of Swab Samples With HSV-2 DNA > 4 log10 Copies/mL for Positive Swab Samples During the Swabbing Period
Time Frame: Day 8 to Day 38
Day 8 to Day 38
Proportion of Swab Samples With HSV-2 DNA > 4 log10 Copies/mL for Positive Swab Samples in the Absence of Lesions (Subclinical Shedding) During the Swabbing Period
Time Frame: Day 8 to Day 38
Day 8 to Day 38
Plasma Pharmacokinetic (PK) Parameters: Cmax of GS-1179
Time Frame: Day 1 up to 92 days

Cmax is defined as the maximum observed concentration of drug at steady state.
Day 1 up to 92 days
Plasma PK Parameters: AUCtau of GS-1179
Time Frame: Day 1 up to 92 days

AUCtau is defined as the area under the concentration versus time curve over the dosing interval at steady state.
Day 1 up to 92 days
Plasma PK Parameters: Ctrough of GS-1179
Time Frame: Day 1 up to 92 days

Ctrough is defined as the observed drug concentration at the end of the dosing interval at steady state.
Day 1 up to 92 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Gilead Sciences

Investigators

  • Study Director: Gilead Study Director, Gilead Sciences

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

November 1, 2026

Primary Completion (Estimated)

November 1, 2027

Study Completion (Estimated)

November 1, 2027

Study Registration Dates

First Submitted

October 28, 2026

First Submitted That Met QC Criteria

October 28, 2026

First Posted (Actual)

November 3, 2026

Study Record Updates

Last Update Posted (Actual)

November 3, 2026

Last Update Submitted That Met QC Criteria

October 28, 2026

Last Verified

October 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • GS-US-578-8029

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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