Adds BioNTech comment in paragraph 4

By Blake Brittain

July 20 (Reuters) - Moderna has countered a patent-infringement lawsuit brought by biotech company CureVac in Delaware federal court over its blockbuster COVID-19 shots, arguing that the lawsuit breaks an agreement between the companies.

Moderna said in a court filing on Friday that CureVac had agreed not to sue in exchange for permission to call a Moderna-affiliated expert witness in another case against BioNTech 22UAy.DE, and that CureVac filed the lawsuit to "harass" Moderna after it was later acquired by BioNTech.

Moderna also argued that its vaccines did not infringe the patents and that the patents are invalid for other reasons, including that CureVac withheld relevant information from the U.S. Patent and Trademark Office during its patent application process.

A BioNTech spokesperson said on Monday that the company will "respond to Moderna's statements in the appropriate forum" and "continue to vigorously defend our unwavering stance towards our innovations."

Spokespeople for Moderna did not immediately respond to a request for comment on the filing on Monday.

CureVac sued Moderna in April, alleging that Moderna copied its technology for stabilizing fragile mRNA to ​use in its vaccines.

The case is part of a wave of high-stakes patent lawsuits from biotech companies seeking royalties for the technology used ​in blockbuster ​COVID-19 vaccines. ⁠Moderna sued Pfizer PFE.N and BioNTech for patent infringement over their shot Comirnaty in 2022, in a ​lawsuit that is ongoing.

Germany-based BioNTech acquired CureVac last year. BioNTech filed a separate ​U.S. patent lawsuit against Moderna over its next-generation COVID-19 shot mNEXSPIKE in February.

Moderna called both lawsuits "baseless" in its Friday filing. It also said that CureVac had promised in 2023 not to sue the company over some of the patents after Moderna agreed to waive a conflict of interest for an expert witness in CureVac's patent lawsuit against BioNTech. That witness had previously testified for Moderna in a separate COVID-19 patent case.

Moderna's filing did not include specific details of the companies' agreement.

"CureVac cannot be allowed to profit from breaking its promise," Moderna said in the filing.

The case is CureVac SE v. Moderna Inc, U.S. District Court for the District of Delaware, No. 1:26-cv-00475.

For CureVac: Steven Maslowski, Matthew Pearson and Rachel Elsby of Akin Gump Strauss Hauer & Feld; Mark Izraelewicz, Kevin Flowers and Sandip Patel of Marshall Gerstein & Borun

For Moderna: Kevin Prussia, Emily Whelan, Andrew Danford, Timothy Cook and Laura Macro of Wilmer Cutler Pickering Hale & Dorr

Read more:

CureVac sues Moderna for patent infringement over COVID-19 vaccines

BioNTech sues Moderna for patent infringement over COVID shots