GSK shingles candidate hits its mark in hefty Phase III study

More than four years ago, GlaxoSmithKline ($GSK) began a Phase III study of a shingles candidate it hoped would eventually mount a challenge to Merck's ($MRK) Zostavax. Now, that candidate is one step closer after hitting its primary endpoint in that trial.

HZ/su, which combines a protein found on the shingles-causing virus with an adjuvant system to amp the vaccine up, cut the risk of shingles by 97.2% in adults aged 50 and older compared with placebo, the pharma giant said Thursday. The study, which kicked off back in August of 2010, spanned 18 countries and involved more than 16,000 participants.

"It's great news that the ZOE-50 trial has met its primary endpoint," GSK's vaccine development leader Alain Brecx said in a statement. "… 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."

Right now, Merck's Zostavax is the only vaccine out there to protect against the painful skin rash, which affects about a million people per year in the U.S., according to the CDC. The Merck vaccine pulled in $653 million last year for the New Jersey drugmaker, taking the company's No. 3 spot behind global behemoth Gardasil and the ProQuad/M-M-R II/Varivax group.

GlaxoSmithKline is hoping a challenger will help it leapfrog Merck, the worldwide vaccines leader by 2013 sales, in the standings--a prospect that looks good after its April agreement to acquire the majority of Novartis' ($NVS) vaccines business.

Last year, Merck, second-place trailer Sanofi ($SNY) and Glaxo put up revenue numbers that all hit within $420 million of one another. But Novartis' unit raked in $1.42 billion of its own, and in announcing the companies' multi-billion-dollar asset swap earlier this year, GSK said it expected deal-related revenues to touch £1.3 billion--14% of which the vaccines side would generate.

- read Glaxo's release

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