Sanofi, Regeneron score win against Amgen patents on PCSK9 med Repatha

A judge on Wednesday ruled against Amgen in a PCSK9 patent fight. (Amgen)

Sanofi and Regeneron have been battling with PCSK9 rival Amgen over patents on their cholesterol drugs for years, with Amgen at one point blocking sales of the partners’ Praluent. Now, Sanofi and Regeneron have persuaded a judge that certain claims of two Amgen patents covering PCSK9 med Repatha are invalid. 

In a 34-page opinion Wednesday, Judge Richard Andrews wrote that Amgen’s patents, as written, require “undue experimentation ... to practice the full scope of the claimed invention.” The judge additionally rejected Sanofi and Regeneron's motion for a new trial and Amgen’s motion for a permanent injunction against Praluent sales. 

Previously, a jury found two of Amgen's patent claims invalid. With the judge's new ruling, Sanofi and Regeneron have invalidated all 5 of the Amgen patent claims they contested, Sanofi said in a Wednesday statement.

“It has been our longstanding belief that all of Amgen’s asserted U.S. PCSK9 patent claims are invalid, and we are pleased today’s decision reaffirms this,” Sanofi's general counsel Karen Linehan said in a statement.

An Amgen representative said the company disagrees with the ruling and will seek a review by the appellate court.

"Protecting intellectual property is critical to our business since it allows for our investment in the research and development of new medicines," she added. "Consequently, we are disappointed with today’s decision, and we look forward to presenting our case to uphold the jury’s verdict."

The case features years of legal back-and-forth. First, Amgen sued Sanofi and Regeneron way back in 2014 alleging patent infringement. The sides took the case to trial in March 2016, and a jury found certain Amgen patents valid. The company moved for an injunction against Praluent sales, which was granted but later vacated. 

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During the appeals process, the federal court found errors during the legal process and sent the case back to Delaware court for a new trial. After the newer trial, the jury found certain Amgen patent claims valid and others invalid. Amgen sought an injunction against its rivals, while Sanofi and Regeneron sought to overturn the jury verdict. Those motions led to Judge Andrews' Wednesday decision.

The legal saga comes as both drugs have failed to live up to early sales estimates, partly due to high prices that caused payers to put up barriers to access. More recently, the rivals significantly discounted their drugs in a bid for better access. Amgen reported $152 million in second-quarter Repatha sales, while Sanofi and Regeneron reported $74 million for Praluent.

Regeneron's share price closed up more than 2% after the decision Wednesday.