By Blake Brittain

March 5 - Pfizer PFE.N and BioNTech 22UAy.DE won a round in their legal battle with Moderna MRNA.O over COVID-19 vaccine patents on Wednesday, convincing a U.S. Patent Office tribunal that two patents Moderna accused them of infringing were invalid.

The Patent Trial and Appeal Board agreed with Pfizer and its German partner that Moderna's patents were invalid based on "prior art" that disclosed the inventions before Moderna patented them. The decision, which is currently sealed, can be appealed to the U.S. Court of Appeals for the Federal Circuit.

Spokespeople for Moderna did not immediately respond to a request for comment on the ruling. Pfizer and BioNTech said in company statements that the decision confirms their position that the two Moderna patents are invalid.

Defendants frequently turn to the board, which hears challenges to patent validity, as an alternative path to fend off patent infringement claims. Moderna sued Pfizer and BioNTech in federal court in Massachusetts in 2022 for allegedly infringing its patents in a lawsuit that is still ongoing.

Pfizer and BioNTech have separately challenged the validity of Moderna's patents in the court case, which also involves an additional patent not covered by Wednesday's decision.

Pfizer and its German partner told the board in 2023 that the Moderna patents were "unimaginably broad" and covered a "basic idea that was known long before" their invention date of 2015.

They argued that scientists discovered mRNA could be used for vaccines as early as 1990, and that Moderna's patents were invalid because their innovations were noted in publications from as early as 2004.

Moderna responded that it was first to discover the patented technology and that its mRNA inventions "changed fundamental assumptions in pandemic preparedness."

Pfizer and BioNTech earned more than $3.3 billion in revenue from global sales of their vaccine Comirnaty last year, while Moderna earned $3.2 billion from its vaccine Spikevax, according to company reports. Sales of both vaccines declined significantly between 2023 and 2024.

A German court separately ruled earlier Wednesday that Pfizer and BioNTech infringed a European Moderna patent and owed Moderna an amount of damages yet to be determined.

The cases are BioNTech SE v. ModernaTX Inc, Patent Trial and Appeal Board, Nos. IPR2023-01358 and IPR2023-01359.

Read more:

Moderna sues Pfizer/BioNTech for patent infringement over COVID vaccine

Pfizer, BioNTech challenge Moderna COVID-19 vaccine patents at US Patent Office

Pfizer wins pause on Moderna's COVID-19 patent lawsuit