he Food and Drug Administration on Friday approved a second shingles vaccine, giving pharmaceutical giant GlaxoSmithKline a go-ahead to market Shingrix in the United States.
The FDA approval marks the second regulatory green light for the vaccine in a week’s time. Last Friday Shingrix was approved for sale in Canada. Regulatory filings are also in the works for the European Union, Australia, and Japan, GSK said.
The vaccine offered 98 percent protection in the first year and that protection remained at 85 percent or higher three years after vaccination — stronger protection than the only other shingles vaccine on the market, Merck’s Zostavax.
GSK has been keenly awaiting the FDA’s ruling, eager to get to market a vaccine analysts estimate could reach $1 billion a year in sales by 2022.
“We are absolutely thrilled to get to this point because the science behind this vaccine offers tremendous potential for helping patients, protecting them against getting shingles and its complications,” said Dr. Leonard Friedland, vice president for scientific affairs and public health for GSK’s North American vaccines unit.
Shingles is a delayed complication of chickenpox, a highly infectious disease most children suffered through in the era before the chickenpox vaccine was developed.
People who have had chickenpox harbor the varicella zoster virus — the bug that causes the disease — in their bodies after infection.
Healthy immune systems keep the virus in a dormant state. But people who have weakened immune systems, either because of an illness or because the immune system declines with age, can develop shingles.
The condition typically manifests as a painful, itchy rash, either on one side of the torso or one side of the face. The blisters can lead to ulcers and scars.
“There’s nothing good about shingles,” said Dr. Anne Louise Oaklander, a shingles expert who is director of the nerve unit at Massachusetts General Hospital.
“And it can be quite bad. In the worst cases, people may not be able to put their clothing on. And it can leave ulcers and scars.”
Shingles can also lead to strokes, vision and hearing loss, and other complications, Oaklander said.
The condition generally clears up within a few weeks. But some people who have had shingles go on to develop what’s known as post-herpetic neuralgia, in which nerve pain persists for months and sometimes years. The risk of developing post-herpetic neuralgia rises with age.
“This can be absolutely debilitating,” said GSK’s Friedland. “That is the type of pain that changes people’s lives. They have difficulty sleeping and working and doing the things that they want to do.”
Oaklander welcomed the news of the approval of the new vaccine, saying that more adults should be vaccinated against shingles.
In the United States alone, there are an estimated 1 million cases of shingles a year, and one in three people can expected to develop the condition during their lifetime. One in five people who have shingles will develop post-herpetic neuralgia.
“The potential for this vaccine to avert so many cases of shingles in our older population is just really exciting,” Friedland said.
Shingrix, which should be available to consumers before the end of the year, could take a big bite out of Merck’s market share.
Market projections for the two-dose Shingrix are strong. EvaluatePharma estimates the worldwide sales potential for the vaccine to top $1 billion a year within five years. Meanwhile the forecasting firm projects worldwide sales of Zostavax to fall from $729 million this year to just under $600 million in 2022.
EvaluatePharma, which derives its forecasts by averaging the estimates of a number of stock market analysts, predicts U.S. sales of Shingrix could reach $583 million by 2022, and should outstrip Zostavax’s U.S. sales in 2020. It projects that domestic sales of Zostavax will drop by nearly 31 percent by 2022, falling to $337 million from $491 million this year.
Critical to the performance of the new vaccine will be decisions that will come next week, at a meeting of the Advisory Committee on Immunization Practices. The ACIP — an expert panel that advises the Centers for Disease Control and Prevention on vaccine issues — is expected to vote Wednesday to recommend use of this vaccine in adults 50 and older.
It may also vote to recommend the vaccine on a preferential basis — in other words, suggest that doctors use the GSK vaccine over the Merck one. At a meeting of the committee in June, a CDC vaccine expert who heads a Shingrix work group, Dr. Kathleen Dooling, alerted the ACIP to the fact the work group was leaning toward proposing a preferential recommendation for the new vaccine.
Dooling said the majority of members of the working group supported the idea. They were concerned, she said, that if a preference wasn’t named, insurance companies might opt to reimburse for the cost of the cheaper vaccine — regardless of which is best. And it would require time-strapped doctors to try to figure out which vaccine to give their patients.
Zostavax offers moderate protection against shingles and post-herpetic neuralgia in the first few years after vaccination — 51 percent and 67 percent, respectively. But the protection wanes quite quickly and appears to be gone within seven to nine years after vaccination.