Pfizer: sued in Europe by Enanta for patent infringement

Published: 2025-08-21 03:14:16 ET PFE

Published on 08/21/2025 at 03:14 am EDT

US biotech company Enanta Pharmaceuticals announced on Wednesday that it had filed a complaint with the EU's Unified Patent Court (UPC) against pharmaceutical giant Pfizer, accusing it of infringing a European patent in connection with the development and marketing of its antiviral treatment for Covid-19, Paxlovid.The Massachusetts-based biotech company said the proceedings target Pfizer's activities in the 18 EU countries that are currently members of the court.In a statement, Enanta argues that the granting of European patent No. 265 by the European Patent Office, published today in the European Patent Bulletin, is in fact based on an application filed in July 2020, which described the functioning of the coronavirus protease inhibitors developed by Enanta's researchers.The company emphasizes that patent '265' is the European equivalent of US patent No. 11,358,953, which is also at the heart of ongoing litigation between Enanta and Pfizer in the US.In accordance with UPC procedures, a hearing on the infringement action is expected to take place within 12 months, with a decision being handed down in the following weeks.If infringement is found, further proceedings would be necessary to assess damages.The UPC is a supranational court that allows holders of unitary patents and European patents to enforce their patents and third parties to obtain the revocation of patents in all EU member states that have ratified the agreement.Pfizer's Paxlovid, a combination of two antivirals for the treatment of adults with mild to moderate Covid who are at high risk of developing severe disease, including hospitalization or death, was approved in the UK in 2021.On the New York Stock Exchange, Pfizer shares actually closed up slightly (+0.2%) on Wednesday morning, while Enanta shares (+5.1%) clearly benefited.