GlaxoSmithKline (GSK) has reported positive phase III trial data for a new shingles vaccine that could be the first major competitor to Merck & Co’s Zostavax.
Shingles, also known as herpes zoster, is a painful skin rash caused by the reactivation of the chickenpox virus in people who have previously had the illness.
It can be extremely painful and in some cases leads to long-term pain (post-herpetic neuralgia) that does not resolve after the skin lesions have healed and can last for years.
The HZ/su vaccine cut the risk of shingles developing in people aged over 50 by 97% compared to placebo in the 16,000-patient ZOE-50 study, which got underway in 2010. In trials, Zostavax’ protective efficacy was around 70%, although there are no direct head-to-head comparisons of the two vaccines.
The vaccine – which has been predicted to become a $1bn-a-year product if approved – is administered in two doses two months apart by intramuscular injection, while Zostavax is given in a single shot. GSK’s vaccine is based on a protein called gE found on the herpes zoster virus, while Zostavaz is a live, attenuated form of the zoster virus.
Merck reported Zostavax sales of $758m in 2013, a 16% increase on the prior year as take-up in elderly patients continues to grow thanks to a new direct-to-consumer (DTC) advertising campaign.
HZ/su also includes Agenus’ AS01B adjuvant, which was also used in the company’s RTS vaccine for malaria and MAGE-A3 vaccine, which flunked trials in melanoma and lung cancer. Shares in Agenus climbed more than 17% on the news
“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,” said Alain Brecx, vaccine development leader at GSK.
The company said the safety data from the trial would be analyst by its independent data monitoring committee over the coming months, but as of the last review at the end of May no serious side effects had been identified.
GSK has not indicated when it hopes to file for approval of HZ/su, but said it currently has other studies ongoing to test the vaccine’s safety and efficacy in people aged 70 and older and in immunocompromised people and will be reporting additional clinical data in 2015.