12:55 PM EDT, 04/25/2024 (MT Newswires) -- (Updates with comments by GSK and BioNTech starting in the fourth paragraph)

GSK (GSK) filed a lawsuit against Pfizer ( PFE ) and BioNTech (BNTX) in a Delaware federal court on Thursday, alleging patent infringement related to the messenger RNA, or mRNA, technology used in the Pfizer-BioNTech Comirnaty COVID-19 vaccines.

GSK said in the lawsuit filed in the United States District Court for The District of Delaware that the Comirnaty vaccines infringe one or more patents issued to GSK's GSK Biologicals unit for the mRNA technology, which was developed "more than a decade before" the COVID-19 pandemic.

A Pfizer ( PFE ) spokesperson told Reuters in a statement that the company was "confident in our IP position around Comirnaty" and plans to "vigorously defend" against the claims filed by GSK.

"GSK is committed to taking appropriate action where necessary to protect the company's intellectual property and believes that these patents provided the foundational technology used in Pfizer ( PFE ) and BioNTech's COVID-19 mRNA vaccines," a GSK spokesperson said in an emailed statement to MT Newswires. "We are willing to license these patents on commercially reasonable terms and to ensure continued patient access."

BioNTech declined to comment on the "company's legal strategy," while Pfizer ( PFE ) did not immediately respond to a request for comment.

Shares of GSK were little changed in recent Thursday trading. Pfizer ( PFE ) slumped 3.2%, and BioNTech fell 1.4%.

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