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By Gene Emery
Sept 14 (Reuters) - GlaxoSmithKline's experimentalvaccine to prevent the intensely painful condition known asshingles remained 90 percent effective in people over age 70even four years after receiving the injection, according to datapublished on Wednesday.
In clinical trials, GSK's Shingrix has shown greaterprotection for older recipients than what has been demonstratedby Merck & Co's rival Zostavax vaccine. The drug is oneof GSK's biggest new product hopes. It plans to file for U.S., European and Japanese approval this year, and the vaccine couldreach the market in 2017.
The latest four-year data on Shingrix, which appears in theNew England Journal of Medicine, shows it may also provide anadditional significant advantage by maintaining itseffectiveness over time.
"It's a real step forward for vaccinology for elderlypatients," the study's lead author, Dr. Anthony Cunningham ofthe Westmead Institute for Medical Research in Australia, saidin a telephone interview.
Zostavax efficacy declines with age, dropping to only about18 percent in adults over 79 versus 70 percent for people intheir 50s. A Kaiser Permanente study found it was 69 percenteffective in patients age 60 and older, yet only 4.2 percentremained protected seven years later.
Researchers found no such drop with GSK's vaccine in thestudy of 13,900 volunteers over age 69.
"Although the follow-up period was limited to four years,there was little decline in effectiveness in the years followingvaccination," said Dr. Susan Rehm, vice chairwoman of thedepartment of infectious disease at the Cleveland Clinic, whowas not involved in the study.
GSK had previously reported 90 percent protection withShingrix in recipients over age 69.
It worked as well among people in their 70s as it did inpeople in their 80s and 90s, and that effectiveness "wasmaintained for the duration of the trial," said Dr. KathleenNeuzil of the University of Maryland School of Medicine and Dr.Marie Griffin of Vanderbilt University Medical Center, in aJournal editorial.
It also protected against residual pain caused by shinglesin 89 percent of cases.
The risk of shingles, which is caused by reactivation of thechicken pox virus, increases with age. There are about 1 million cases of shingles in the United States each year,according to the Centers for Disease Control and Prevention.
Analysts are forecasting global Shingrix sales reaching $1.2billion in 2021, according to Thomson Reuters Cortellis. Thevaccine contains a component from U.S. biotech Agenus Inc, which is entitled to royalties on future sales, but nolive virus.
The GSK vaccine was administered in two doses given twomonths apart, while Merck's is given in one injection.
Nearly 80 percent of those who received Shingrix had areaction to the shot, such as arm soreness, including 12 percentwhose reaction was serious enough to prevent normal activity.That compared with rates of 30 percent and 2 percent for thosewho received a placebo. (Reporting by Gene Emery in Cranston, Rhode Island; Additionalreporting by Ben Hirschler in London; Editing by Bill Berkrotand Matthew Lewis)
