- GlaxoSmithKline plc on Friday secured a key approval from the Food and Drug Administration for its shingles vaccine Shingrix, boosting the growth potential for the British drugmaker's vaccines business as the company turns to new drugs to recharge revenues.
- The regulatory OK will put GSK in direct competition with Merck & Co, which currently markets the only approved vaccine for the painful rash caused by the varicella zoster virus. Over the past three years, Merck's Zostavax has earned the pharma nearly $2.2 billion in sales.
- GSK thinks Shingrix, which showed higher efficacy than Merck's product in adults aged 50 years and older, has the potential to reach more patients and become the company's top-selling vaccine in short order.
When GSK CEO Emma Walmsley laid out a new direction for the company's drug development efforts this past July, she identified three programs that would be crucial near-term opportunities for the company. The three — Shingrix, recently approved lung drug Trelegy Ellipta (fluticasone furoate, umeclidinium & vilanterol) and two-drug HIV regimens — should help offset looming declines in sales of the mainstay Advair franchise.
Success with Shingrix opens up a potentially billion-dollar market for GSK. Merck's Zostavax currently earns roughly $700 million a year in sales. GSK, however, estimates that Zostavax only reaches about 30% of the potential patient population and believes Shingrix's superior efficacy could make it a more meaningful treatment for a wide group of patients.
"We have said that Shringix will be a contributor of around a third of our [vaccine business'] growth and we do believe that could be our biggest vaccine," Walmsley told investors in July.
In clinical studies, Shingrix showed greater than 90% efficacy across all age groups, sustained across four years of follow-up. That broad benefit is an important advantage as the efficacy of Merck's Zostavax appears to decline in older patients.
"The risk and severity of shingles increases with age as the immune system loses the ability to mount a strong and effective response to infection," said Thomas Breuer, chief medical officer of GSK Vaccines, in a Oct. 20 statement on the approval. "Shingrix was developed specifically to overcome the age-related decline in immunity."
Shingrix could get a further boost this week if an advisory committee to the U.S. Centers for Disease Control and Prevention recommends the vaccine's use. The group is expected to vote at its October 25 meeting.
GSK has also filed the vaccine for approval in the European Union, Australia and Japan.