Enanta Sues Pfizer For Patent Infringement in COVID-19 Antiviral Paxlovid

Enanta Sues Pfizer For Patent Infringement in COVID-19 Antiviral Paxlovid

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Enanta Pharmaceuticals filed a patent infringement lawsuit against Pfizer for the latter's alleged use of its proprietary antiviral component in the production of the COVID-19 antiviral Paxlovid.

In the complaint filed with the U.S. District Court for the District of Massachusetts, the Delaware-headquartered biotechnology firm is seeking court acknowledgment of the infringement and damages, coverage of legal fees and other further relief. 

Enanta claims Pfizer willfully and deliberately violated its patent when it used antiviral 3CL protease inhibitor candidates in Paxlovid's design, particularly EDP-235, which Entanta identified in early 2021 to be its lead compound for its COVID-19 program. Pfizer's nirmatrelvir, the product's main component, is a SARS-CoV-2 3CL protease inhibitor.

Enanta dosed its first human subject in a Phase I trial in February and was granted Fast Track designation by the U.S. Food and Drug Administration in March. 

Enanta filed its U.S. Provisional Patent Application in July 2020 ('048), then a utility patent application in July 2021 claiming priority over the '048 application. In November 2021, it filed U.S. Patent Application No. 17/522,176 ('176) to further support priority claims made in the previous application. Finally, after the U.S. Patent Office recognized Enanta's innovation in June, the company was given the '953 Patent, which Enanta claims Pfizer violated in its latest court complaint. 

"Pfizer has infringed and is continuing to infringe at least one claim of the '953 patent pursuant to 35 U.S.C. § 271(b) by actively inducing the manufacture, use, sale, or offer for sale within the United States, and/or by the import into the United States, of its Paxlovid product... Pfizer has committed and continues to commit these acts of infringement without license or authorization," the document read.

To be clear, Enanta wrote that it is not looking to stop the distribution of Paxlovid or to take the matter to litigation, as it recognizes the importance of the drug. However, the company said it needs fair compensation for Pfizer's use of the 3CL protease inhibitor that Enanta's scientists discovered. Enanta is seeking "treble damages" for Pfizer's willful infringement and other financial compensation related to the issue. 

"Pfizer's infringement has damaged and will continue to damage Enanta, which is entitled to recover damages adequate to compensate for Pfizer's infringement in an amount to be determined at trial, and in any event, no less than a reasonable royalty for the use made by Pfizer of Enanta's invention," added the complaint. 

Pfizer has yet to comment on the matter. 

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