GSK is ending further development of its therapeutic vaccine for herpes after the candidate failed to prevent recurrent symptom flare-ups in infected adults in a mid-phase trial.
The vaccine, known as GSK3943104, is currently the only asset for herpes in GSK’s infectious disease pipeline. It is designed to prevent outbreaks of genital sores or blisters in people who already carry the virus.
The candidate did not meet the Phase 2 primary efficacy endpoint of time until the first confirmed herpes simplex virus type 2 (HSV-2) episode versus placebo in the Phase 1/2 proof-of-concept study, according to a Wednesday release. The Phase 2 portion was evaluating the asset in 240 people aged 18 to 60 with recurrent genital herpes with at least three episodes in the past year, according to a company presentation.
GSK said it will continue with routine safety monitoring of the patients involved, but no longer plans to advance the program through Phase 3 studies. But the company said it will use findings from the failed study to support future R&D efforts in the disease.
Genital herpes is often caused by HSV-2, which affects around 491 million people worldwide, according to the WHO. There is no cure, but available treatments can help prevent or shorten outbreaks or reduce the risk of passing the infection on to sexual partners. Women with another virus, HPV, may have a greater risk of cervical cancer if they also have genital herpes.
In May, Moderna announced it had completed enrollment of 300 people into its Phase 1/2 trial of mRNA-1608 in adults with recurrent HSV-2 genital herpes. BioNTech kicked off a Phase 1 test of its prophylactic candidate back in 2022.
Creating new vaccines and treatments for herpes has also been the target of smaller biotechs. Germany’s AiCuris has an antiviral candidate dubbed pritelivir in Phase 3 trials for immunocompromised people with resistant forms of HSV. Meanwhile, Woburn, MA-based Rational Vaccines is taking a more traditional approach by developing attenuated live viral vaccines for the infection.
Editor’s Note: This article was updated to clarify the link between HPV, genital herpes and cervical cancer.