GSK4108771A
phase 1 GlaxoSmithKline
Last updated:
| Developer | GlaxoSmithKline |
|---|---|
| Platform | other |
| HSV target | unclear |
| Approach | unclear |
| Phase | phase 1 |
| Status | A Phase 1 dose-escalation trial of GSK4108771A was terminated in 2021 to enable development of an enhanced version of the vaccine; as of the 2026-09-27 registry search, no record found has an ongoing status. |
| Trials | NCT04762511 |
GSK4108771A is an HSV vaccine sponsored by GlaxoSmithKline, registered in a phase 1 dose-escalation trial in healthy adults aged 18-40. That trial, the registry record that names GSK4108771A, was terminated in 2021 after 17 actual enrolments, to enable development of an enhanced version of the vaccine, and has no results posted. A separate GSK phase 1/2 trial of an HSV-targeted immunotherapy completed in 2025; its registry listing describes "HSV formulation" arms rather than naming GSK4108771A, so whether it tests the same vaccine is unconfirmed.
What it is
GSK4108771A is an HSV vaccine whose registry trial is sponsored by GlaxoSmithKline. The registry lists lower, low, medium and high dose formulations of the vaccine and a saline placebo, in a dose-escalation design. The sources do not state the vaccine’s platform, which HSV type it targets, or whether it is meant to prevent or treat infection.
Where it stands
NCT04762511 was a Phase 1, single-blind, randomised, placebo-controlled dose-escalation study in healthy participants aged 18-40. It was terminated in 2021 after 17 actual enrolments; the registry gives the reason as enabling development of an enhanced version of the vaccine. No results for it are posted on the registry. A ClinicalTrials.gov search on 2026-09-27 for records naming GSK4108771A (plus seeded trial ids) returned 2 records, and none had an ongoing status. The second of those records, NCT05298254, is a GSK phase 1/2 trial of an HSV-targeted immunotherapy; its listing describes adjuvanted and non-adjuvanted “HSV formulation” arms rather than naming GSK4108771A, so whether it tests the same product is unconfirmed. Its title covers healthy participants aged 18-40 or participants aged 18-60 with recurrent genital herpes. NCT05298254 enrolled 505 participants (actual) and was completed in 2025, with no results posted on the registry.
What this does and doesn’t mean
A registered trial shows the vaccine was tested in people, not that it worked; the terminated GSK4108771A trial has no results posted. The phase 1/2 immunotherapy trial also has no posted results, and its connection to GSK4108771A is unconfirmed.
Registry snapshot
- Registry status
- Terminated
- Phase
- phase 1
- Enrollment
- 17 (actual)
- Lead sponsor
- GlaxoSmithKline
- Started
- Mar 2, 2021
- Primary completion
- May 26, 2021
Why stopped (registry): To enable development of an enhanced version of the vaccine
Registry record last updated Jun 28, 2021.
Sources
- ClinicalTrials.gov registry search for GSK4108771A (searched 2026-09-27)
- A Phase I, Single-blind, Randomised, Placebo-controlled, Dose Escalation Study to Evaluate the Reactogenicity, Safety and Immune Response of an HSV Vaccine in Healthy Participants Aged 18-40 Years (NCT04762511)
- A Phase I/II, Observer-blind, Randomised, Placebo-controlled, Multi-country Study to Evaluate Reactogenicity, Safety, Immune Response, and Efficacy of an HSV-targeted Immunotherapy in Healthy Participants Aged 18-40 Years or in Participants Aged 18-60 Years With Recurrent Genital Herpes (NCT05298254)