Amgen persuades jury to back PCSK9 patents, putting Sanofi and Regeneron back on defense

Praluent is Sanofi and Regeneron's entrant in the PCSK9 class. (Sanofi)

Give the latest round of the PCSK9 patent fight to Amgen. A California jury decided Monday that two key patents protecting its Repatha cholesterol drug are indeed valid—and that puts Sanofi and Regeneron in a tough spot.

The partners, which sell a rival PCSK9 inhibitor called Praluent, previously stipulated that their drug infringed the Amgen patents.

Amgen CEO Bob Bradway said in a release after the verdict that the company is “thankful that the jury weighed the evidence carefully and recognized the validity of Amgen’s patents.”

The battle is far from over, though. Sanofi and Regeneron said in an emailed statement that they plan to pursue every legal avenue necessary to sweep aside the disputed patents, starting with a motion to overturn the jury verdict.

"It is our longstanding belief that all of Amgen's asserted U.S. patent claims are invalid and we believe the law and the facts support our positions,” Sanofi EVP and general counsel, Karen Linehan, said in the statement.

It’s a bit of deja vu: Amgen won in the trial court almost three years ago. That time, the California-based drugmaker persuaded the judge to grant an injunction that would have pushed Praluent off the market, touching off a quick and furious trip to the Federal Circuit Court, which counts patent litigation as a specialty.

It was the Federal Circuit that sent the case back to the district court for a new trial, and if Sanofi and Regeneron don’t prevail at the district court level, they’ll appeal to the Federal Circuit again.

"We will continue to vigorously defend our positions against Amgen's overly broad patent claims," Regeneron EVP and General Counsel Joseph LaRosa said in the statement. "We are considering our next steps in this important case and continue to believe in the differentiated clinical profile of Praluent.”