Moderna on Friday sued Pfizer and its German partner BioNTech for patent infringement in the development of the first COVID-19 vaccine approved in the United States, alleging they copied technology that Moderna developed years before the pandemic.

"We believe that Pfizer and BioNTech unlawfully copied Moderna's inventions, and they have continued to use them without permission," said Moderna Chief Legal Officer Shannon Thyme Klinger in a news release.

The inventions, which Moderna believes are two key features of its patented technologies, are critical to the success of its messenger RNA (mRNA) vaccines, particularly during the development of its own mRNA COVID-19 vaccine, Spikevax. 

"We are filing these lawsuits to protect the innovative mRNA technology platform that we pioneered, invested billions of dollars in creating, and patented during the decade preceding the COVID-19 pandemic," Moderna Chief Executive Stephane Bancel said in the statement.

The lawsuit, which seeks undetermined monetary damages, was being filed in U.S. District Court in Massachusetts and the regional court of Dusseldorf in Germany.

Based in Cambridge, Massachusetts, Moderna had been practicing mRNA vaccine technology for nearly a decade. The Germany-based BioNTech had also been working in this field when it partnered with the U.S. pharmaceutical giant Pfizer.

The U.S. Food and Drug Administration granted emergency use authorization for the COVID-19 vaccine first to Pfizer-BioNTech in December 2020, then one week later to Moderna.

Moderna alleges Pfizer-BioNTech, without permission, copied mRNA technology that Moderna had patented between 2010 and 2016, well before COVID-19 emerged in 2019 and exploded into global consciousness in early 2020.

Early in the pandemic, Moderna said it would not enforce its COVID-19 patents to help others develop their own vaccines, particularly for low- and middle-income countries. But in March 2022, Moderna said it expected companies such as Pfizer and BioNTech to respect its intellectual property rights. It said it would not seek damages for any activity before March 8, 2022.

Pfizer and BioNTech are already facing multiple lawsuits from other companies who say the partnership's vaccine infringes on their patents. Pfizer-BioNTech have said they will defend their patents vigorously.

Moderna has also been sued for patent infringement in the United States and has an ongoing dispute with the U.S. National Institutes of Health over rights to mRNA technology.

(With input from Reuters)