Pfizer sued for patent infringement over COVID-19 drug Paxlovid

Paxlovid is shown in an illustration in Medford
Paxlovid, Pfizer's anti-viral medication to treat the coronavirus disease (COVID-19), is displayed in this picture illustration taken in Medford, Massachusetts, U.S., May 12, 2022. REUTERS/Brian Snyder/Illustration
  • Enanta Pharmaceuticals says Pfizer's blockbuster COVID drug Paxlovid violates its patent
  • Asks court for royalties

(Reuters) - Pfizer Inc's blockbuster COVID-19 treatment Paxlovid violates an Enanta Pharmaceuticals Inc patent for its COVID drug still in development, according to a lawsuit filed Tuesday in Boston federal court.

Watertown, Massachusetts-based Enanta told the court it received the patent for its antiviral medication last week based on applications dating from July 2020. The company said it began human testing for its once-daily, oral COVID treatment in February, and that the Food and Drug Administration fast-tracked its review in March.

Enanta requested an unspecified amount of money damages from Pfizer, including royalties. It also said in a statement that it was not asking the court to block Pfizer from selling Paxlovid.

Paxlovid is an oral antiviral pill for high-risk patients that is intended to stave off serious complications from COVID-19. Pfizer said last month it expects to make $22 billion from Paxlovid sales this year.

The company did not immediately respond to a request for comment on the lawsuit.

Enanta's patent covers a chemical compound that blocks the coronavirus from reproducing. The lawsuit said Paxlovid works in the same way as Enanta's patented antiviral.

The number of patent lawsuits over COVID vaccines and treatments has risen in recent months. Multiple pharmaceutical companies have sued Pfizer and Moderna Inc over technology used in their vaccines, and Regeneron Pharmaceuticals Inc is facing a lawsuit over its breakthrough COVID antibody cocktail.

The case is Enanta Pharmaceuticals Inc v. Pfizer Inc, U.S. District Court for the District of Massachusetts, No. 1:22-cv-10967.

For Enanta: Barbara Fiacco and Donald Ware of Foley Hoag

For Pfizer: not available

Read more:

COVID-19 patent challenges mount as Moderna faces new vaccine lawsuit

Regeneron must face patent lawsuit over COVID-19 treatment

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Blake Brittain reports on intellectual property law, including patents, trademarks, copyrights and trade secrets, for Reuters Legal. He has previously written for Bloomberg Law and Thomson Reuters Practical Law and practiced as an attorney. Contact: 12029385713