(Reuters) - A federal judge on Tuesday refused to throw out a court verdict upholding two Amgen Inc (AMGN.O) patents related to the company's cholesterol drug, a defeat for Sanofi SA (SASY.PA) and Regeneron Pharmaceuticals Inc (REGN.O), which make a rival drug.
In an October 2014 lawsuit, Amgen had sought to stop Paris-based Sanofi and Tarrytown, New York-based Regeneron from selling Praluent, a drug intended to lower bad LDL cholesterol by blocking a protein known as PCSK9.
Amgen makes a rival drug called Repatha, and it said Praluent infringed the Thousand Oaks, California-based company's patents related to the protein. A jury found Amgen's patents valid in March.
Following that verdict, Sanofi and Regeneron moved for U.S. District Judge Sue Robinson, who is presiding over the case, to overturn the verdict and order a new trial. She denied that motion on Tuesday.
Regeneron shares were down 2.6 percent in after-hours trading, and Amgen shares rose 1.6 percent.
"The court's ruling today is an important step in this case and confirms the jury's finding that the patents which protect Repatha are valid and infringed by Sanofi," Amgen spokeswoman Kristen Davis said in an email.
Sanofi spokeswoman Ashleigh Koss said in an email that the company was disappointed with the ruling.
"It is our longstanding position that Amgen's asserted patent claims are invalid, and we intend to appeal today's ruling," she said.
Regeneron, which developed Praluent in partnership with Sanofi, could not immediately be reached for comment.
Damages have yet to be set, and Robinson has not decided whether to block Sanofi and Regeneron from selling Praluent. The defendants said after the verdict that they planned to appeal to the U.S. Federal Circuit Court of Appeals, which reviews patent disputes.
The U.S. Food and Drug Administration approved Praluent and Repatha to reduce bad cholesterol in 2015.
The drugs are more costly than other treatments targeting bad cholesterol, with a list price topping $14,000 annually.
Reporting by Brendan Pierson in New York; Editing by Dan Grebler and Richard Chang