GlaxoSmithKline on Wednesday lifted its long-term outlook following the smash-hit launch of its new RSV vaccine.

The shot targeting the severe and in some cases life-threatening virus booked around £1.2 billion, or $1.5 billion, in sales after only being on the market for roughly half a year. 

GSK in November had forecast 2023 sales for the shot, Arexvy, between £900 million and £1 billion, following its strong launch in the U.S.

The launch of the first-ever vaccines targeting respiratory syncytial virus from GSK and Pfizer last year has proved to be a boon for both companies — though Pfizer saw fewer sales from its shot than its competitor did.

GSK said it now expects to generate more than £38 billion in sales by 2031, up from a previous forecast of £33 billion. In 2023, the British drugmaker raked in £30.3 billion.

GSK now anticipates sales will rise by more than 7% on a compounded annual growth rate between 2021 and 2026, with adjusted operating profit rising more than 11% during that span. In 2021, it had guided for growth rates of more than 5% for revenue and more than 10% for earnings.

The company’s RSV shot in part drove the higher forecast. The vaccine is approved for use in adults aged 60 and older, but could eventually get a greenlight for those ages 50 to 59, Chief Executive Officer Emma Walmsley said on a media call.

An expanded approval of the vaccine could address another 15 million vulnerable patients, she noted. 

“We are really excited about the prospects of this vaccine as part of our high-value portfolio in adult vaccination that will continue to support these upgraded outlooks for the longer term,” Walmsley said.

She added that GSK is planning for at least 12 major product launches, most of which will be in the next four years. 

Arexvy became the world’s first RSV vaccine to win approval from a regulatory body in May following a green light from the U.S. Food and Drug Administration. The shot later won approvals in the U.K., Canada, Japan and several other countries. 

With $1.5 billion in sales last year, Arexvy is now a “blockbuster” vaccine, which is when a product rakes in annual sales of at least $1 billion.

The vaccine has about 70% market share for RSV, Walmsley added Wednesday. That’s a huge edge over GSK’s main rival in the market, Pfizer, which has an RSV vaccine approved for adults ages 60 and older and for expectant mothers who can pass on protection to their children. 

Pfizer’s shot, known as Abrysvo, took in about $890 million in sales last year after its launch, the company announced Tuesday.

Pfizer aims to increase its RSV market share by establishing vaccination as a “year-round discussion” and expanding the company’s retail contracting and offerings, CEO Albert Bourla said during an earnings call Tuesday. The company is also examining the shot in people ages 18 to 59. 

Bourla said during a conference earlier this month that the shot had a “bad launch.” 

Meanwhile, biotech company Moderna hopes to launch its own RSV vaccine this year.

RSV usually causes mild, cold-like symptoms. But each year the virus kills 6,000 to 10,000 seniors and a few hundred children younger than 5 in the U.S., according to the Centers for Disease Control and Prevention. 

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