GSK Discontinues HSV Vaccine After Failed Phase I/II Trial

September 26, 2024 - GlaxoSmithKline (GSK) has announced the discontinuation of its investigational herpes simplex virus (HSV) vaccine candidate, GSK3943104.

This decision follows disappointing results from the TH HSV REC-003 proof-of-concept study, which revealed that the vaccine did not meet its primary efficacy objectives.

As a result, GSK will not advance this candidate to Phase III trials.GlaxoSmithKline (GSK) is a prominent British multinational pharmaceutical and biotechnology company headquartered in London.

Established in 2000 through the merger of Glaxo Wellcome and SmithKline Beecham, GSK has grown to become one of the largest pharmaceutical companies in the world, currently ranking as the tenth largest globally.

Details of the Discontinuation

In its announcement, GSK stated that while the trial found no safety concerns with GSK3943104, it failed to satisfy specific efficacy metrics.

The TH HSV REC-003 trial involved 342 participants and was designed as a randomized, observer-blinded study.

It included two parts: one with healthy volunteers aged 18 to 40 and another with patients aged 18 to 60 who had recurrent genital herpes.

The primary outcome of the study focused on solicited administration site events such as pain and swelling after vaccination.

Additionally, it assessed systemic effects like fever and fatigue.

Despite these efforts, the vaccine did not demonstrate sufficient efficacy in reducing the frequency or severity of HSV-2 related outbreaks.

Implications for HSV Research

The discontinuation of GSK's vaccine candidate highlights the ongoing challenges in developing effective treatments for HSV, which affects millions worldwide.

GSK emphasized the significant unmet medical need for effective therapeutic options for those suffering from recurrent genital herpes.

The company plans to continue collecting safety and follow-up data from the TH HSV REC-003 trial.

This data could provide valuable insights into recurrent genital herpes and inform future research directions within GSK's HSV program.

Currently, GSK has no other candidates for HSV in its pipeline, marking a critical juncture in their research efforts.

Opportunities for Other Companies

With GSK stepping back from HSV vaccine development, attention now shifts to other companies actively pursuing solutions in this space.

Moderna is advancing its mRNA-based candidate, mRNA-1608, which is currently in Phase I/II trials in the U.S.

This innovative approach leverages mRNA technology that gained prominence during the COVID-19 pandemic.

Similarly, BioNTech is developing its own HSV vaccine candidate, BNT163, which entered Phase I trials in December 2022.

Both companies are seen as leading contenders in addressing this long-standing health issue and may offer new hope for effective therapeutic and prophylactic solutions against HSV infections.

Conclusion

The withdrawal of GSK from HSV vaccine development underscores the complexities involved in creating effective treatments for this common virus.

The high prevalence of HSV globally—estimated at over 52 million cases of HSV-2 alone—highlights the urgent need for innovative solutions.

As research continues with companies like Moderna and BioNTech making strides in mRNA technology, there remains hope for developing safe and effective vaccines that can provide relief to those affected by HSV.

The focus will be on overcoming previous challenges to deliver successful therapeutic options in the future.