GSK Sues Pfizer for Alleged RSV Vaccine Patent Infringement

Pictured: GSK sign at its headquarters in London/iStock, William Barton

Pictured: GSK sign at its headquarters in London/iStock, William Barton

GlaxoSmithKline filed a lawsuit against Pfizer on Wednesday for allegedly infringing on four patents related to the antigen used in GSK’s Arexvy respiratory syncytial virus shot, according to multiple media reports.

Papers filed in federal court in Delaware by GSK complain that Pfizer’s RSV vaccine, Abrysvo, “knowingly uses GSK’s claimed inventions” without permission, according to the reports. GSK is demanding a jury trial and seeking monetary damages, including lost profits and royalties resulting from Pfizer’s alleged patent infringement. 

Pfizer denies wrongdoing and says it will defend its position.

The legal complaint comes just months after the companies’ respective RSV vaccines were approved by the FDA. GSK won the FDA’s first-ever nod for its RSV shot Arexvy in early May, followed later that month by the regulator’s approval of Pfizer’s Abrysvo.

Both Arexvy and Abrysvo were approved by the FDA for use in adults 60 and older. Doses are already available to the public at some retail pharmacies, but GSK wants a judge to stop Pfizer from selling its version.

GSK said it was not seeking to limit the use of separate shots of Abrysvo to prevent RSV in infants. The FDA could make a final decision on that vaccine later this month. 

RSV is a common respiratory infection that usually causes mild, cold-like symptoms, but more severe cases kill some 10,000 seniors and a few hundred children under five years of age each year.

The RSV vaccine market could grow to more than $10 billion by 2030, according to analysts. The vaccines are part of both companies’ strategies to replace aging drugs that will face cheaper generic competition.

Pfizer began working on its RSV vaccine program as early as 2013, the lawsuit claims, at least seven years after GSK started its own program. Pfizer knew of GSK’s patented technology since at least October 2019, the legal complaint alleges, when Pfizer began challenging the validity of European versions of the GSK patents. 

News of GSK’s patent dispute with Pfizer comes after AstraZeneca agreed earlier this week to pay rival Bristol-Myers Squibb $510 million to resolve a string of patent-infringement lawsuits filed over blockbuster cancer immunotherapies.

David Adam is a freelance science journalist based in the UK. Reach him at

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