4. Shingrix

GlaxoSmithKline’s shingles vaccine Shingrix nearly crossed the blockbuster threshold by U.S. dollar in its first full year on the market. (GlaxoSmithKline)

4. Shingrix
Company: GlaxoSmithKline
Disease: Shingles
Approved: Oct. 13, 2017 (Canada); Oct. 23, 2017 (U.S.)
First four full quarters sales: £784 million ($999 million)

Like many other drugs on our successful launch list, GlaxoSmithKline's Shingrix represents a major market disruptor. Before Shingrix, Merck & Co.’s Zostavax dominated the market for preventing shingles, a painful disease caused by reactivation of the varicella zoster virus.

Approved in 2006, the Merck shot posted 2016 sales of $685 million. Its 2019 haul? Simply too low to merit a mention in the New Jersey pharma’s annual report.

By contrast, Shingrix nearly crossed the blockbuster threshold by U.S. dollars in its first full year on the market, based on the exchange rates at the end of 2018—and it's kept growing ever since.

Shingrix is an adjuvanted recombinant vaccine, while Zostavax is an old-school live-attenuated version of the varicella zoster virus. As one expert on an independent FDA panel noted in endorsing the vaccine, Shingrix is “a lot better than” Zostavax. And the CDC’s Advisory Committee on Immunization Practices has also been very clear that the GSK shot is the preferred of the two.

In its clinical trial, Shingrix was 97.2% efficacious in people 50 years or older and maintained a high 90% efficacy in those 70 and above for at least four years. In comparison, Zostavax reduces the risk of developing shingles by 69.8% in those ages 50 to 59, and by 51% in individuals older than 60, as its efficacy declines sharply in older patients and wanes over time.

Shingrix immediately ate away Zostavax’s market share. By mid-March 2018, just five months after its launch, Shingrix already accounted for 90% of U.S. shingles vaccine scripts. And by the end of 2018, Shingrix’s market share had reached 98%, according to GSK.

RELATED: JPM: Glaxo sees enormous Shingrix potential, but a supply gap still stands in the way

The huge demand has not only repeatedly wowed industry watchers but also caught GSK off guard. In mid-2018, GSK had to introduce order limits and put its consumer education activities, such as TV advertising, on hold as strong uptake outstripped supply. While it won a fast nod from Chinese authorities in mid-2019, GSK’s only planning a phased launch there to ensure reliable supply.

Despite the production constraints, Shingrix still wrapped up its second full year on the market with fourth-quarter 2019 sales that more than doubled year-over-year to £532 million. By then, the vaccine had been given to an estimated 14 million people in the U.S., CEO Emma Walmsley said during a February 2020 conference call.

GSK has made plans to increase its manufacturing capacity for the vaccine, including building a new site at an undisclosed location to complement its existing bioreactor in Belgium. When it’s up and running, the new site could produce additional doses in the tens of millions.

That'll take time, however, and the British pharma’s only seeing “limited opportunity for further growth beyond 2020 until we bring our new facility online, which we don’t expect before 2024,” Walmsley told investors during the February call.

4. Shingrix