GSK has announced the publication of detailed results from a randomized phase III study (ZOE-70) of its investigational shingles vaccine, Shingrix, showing 90% efficacy in adults aged 70 years and older that is maintained for at least four years. The results were published in the New England Journal of Medicine (NEJM).

The study, from which headline results were reported in October 2015, showed that the two-dose candidate shingles vaccine had 90% efficacy (95% confidence interval: 84-94%) compared to placebo in people over 70 years old. Vaccine efficacy was maintained across the various age groups included in the study, ranging between 90% in people aged 70 to 79 years (95% confidence interval: 83-94%) and 89% in those aged 80 years and above1 (95% confidence interval: 74-96%).

The high efficacy is in line with the results of the ZOE-50 trial, a study in people over 50 years old which was presented and published last year showing a 97% efficacy (95% confidence interval: 93-99%). A pooled analysis of data from both trials showed the vaccine demonstrated 91% efficacy against shingles (95% confidence interval: 86-95%) in adults aged 70 years and older compared to placebo1. This efficacy was maintained with an 88% reduction in the risk of shingles (95% confidence interval: 73-95%) in the fourth year after vaccination.

The risk of serious adverse events, potential immune-mediated diseases or deaths observed in ZOE-70 was similar in people receiving Shingrix and placebo. The most commonly reported local adverse reaction was pain at the injection site and the most frequently reported systemic adverse reaction was fatigue. The majority of injection site and systemic reactions occurred within seven days of vaccination, with most lasting one to three days, and generally were mild-to-moderate in intensity.

In addition, a pooled analysis of data from the ZOE-70 and ZOE-50 trials showed that the candidate vaccine effectively reduced the risk of subsequent chronic neuropathic pain, also known as postherpetic neuralgia (PHN), which is the most common, and often severe, complication of shingles. The candidate vaccine was shown to be 89% (95% confidence interval: 68-97%) efficacious in preventing PHN in people aged 70 years and older and 91% efficacious (95% confidence interval: 75-98%) in people aged 50 years and over.

Dr Emmanuel Hanon, senior vice president, Vaccines Research and Development, GSK, said: “This is the first time that such high efficacy has been demonstrated in a vaccine candidate for older people and it is remarkable, as we know that these people frequently have an age-related weakening of their immune system. If approved, this candidate vaccine could be an important tool for the prevention of shingles and the pain associated with it, which would significantly impact the health and quality of life of so many people.”

Anthony Cunningham, executive director of the Westmead Institute for Medical Research in Australia and Principal Investigator of the ZOE-70 study said: “These data show that this investigational vaccine maintains high efficacy against herpes zoster in people over 70 and 80 years of age, the age groups who are most affected by the disease. Importantly, it also prevents a common and feared complication of herpes zoster, prolonged pain, or post herpetic neuralgia in these groups.”

Based on these and the previously reported ZOE-50 data, GSK expects to start submitting regulatory applications for the candidate vaccine for the prevention of shingles in people 50 years and above later this year.