GSK announced that a pivotal phase III study to assess the efficacy of HZ/su, an investigational vaccine for the prevention of shingles, has met its primary endpoint.

Analysis of the primary endpoint showed that HZ/su reduced the risk of shingles by 97.2 per cent in adults aged 50 years and older compared to placebo. These are the first results from the ZOster Efficacy study in adults aged 50 years and over (ZOE-50). The study, which started in August 2010, is ongoing in 18 countries and involves more than 16,000 individuals.

Alain Brecx, MD, Vaccine Development Leader at GSK said: “It’s great news that the ZOE-50 trial has met its primary endpoint and I would like to thank all those involved in the clinical development programme. If approved, this candidate vaccine may offer an important option for the prevention of shingles, a painful disease that negatively impacts peoples’ health and quality of life. We look forward to sharing these compelling results and additional data from the ZOE-50 study and the broader HZ/suclinical development programme with the scientific and regulatory communities.”

HZ/su is a new candidate vaccine that combines gE, a protein found on the virus that causes shingles, with an adjuvant system, AS01B,1 which is intended to enhance the immunological response.

The full set of safety data from the ZOE-50 trial is currently being analysed and will be disclosed in the coming months. The Independent Data Monitoring Committee (IDMC) for the ZOE-50 study, in its ongoing review of the safety information up to 31 May 2014, raised no concerns regarding the continuation of the trial. At this time, the safety profile of HZ/su in older adults is based on data from more than 440 subjects who received HZ/su in phase I and II clinical trials. The most common adverse events seen with HZ/su from these studies included local reactions (pain, redness, swelling at the injection site) and systemic symptoms (muscle pain, fatigue and headache).

Data from the ZOE-50 trial are expected to be presented at a forthcoming scientific conference and submitted for publication in a peer-reviewed journal.

Additional trials to evaluate the ability of HZ/su to prevent shingles are underway in people aged 70 and older and in immunocompromised people. These studies will evaluate the efficacy, safety, and immunological response of HZ/su in specific populations and whether it can prevent some of the complications of shingles, such as chronic neuropathic pain, also known as post-herpetic neuralgia (PHN).