Sanofi, Regeneron one step closer to owing PCSK9 royalties as judge upholds Amgen patent ruling

Repatha pack and injector
A judge has ruled that Sanfofi and Regeneron's PCSK9 inhibitor Praluent infringes the patents on Amgen's Repatha.

Amgen has been in a tight race with Sanofi and Regeneron to win market acceptance for a new class of drugs that fight ultra-high cholesterol by inhibiting an enzyme called PCSK9—a fight that includes a patent-infringement claim. On Tuesday, Amgen kept the upper hand in that patent case, which could put the company in line to collect royalties from Sanofi's and Regeneron's treatment.

Back in March, a Delaware jury ruled that Sanofi and Regeneron’s PCSK9 inhibitor, Praluent, infringed patents on Amgen’s drug in the same class, called Repatha. Judge Sue Robinson threatened to block Praluent sales unless the parties struck a royalty agreement. Sanofi and Regeneron asked her to overturn the verdict and order a new trial. She denied the motion, according to court documents filed Tuesday.

A Sanofi spokeswoman said the company is 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 via email.

An Amgen spokeswoman, however, called judge's decision "an important step in this case." The ruling "confirms the jury's finding that the patents which protect Repatha are valid and infringed by Sanofi," the spokeswoman said.

The patent battle is complicating what has already been a tough market entrée for PCSK9 inhibitors. The drugs, which must be injected, cost about $14,000 a year—way more than statins, many of which are already off patent and cost just pennies a pill. Amgen has been busy making improvements to its product, introducing a version in July that can be injected once per month instead of every two weeks.

Still, payers have put up roadblocks for sales of both drugs, requiring physicians to gain preapprovals before prescribing them. Both doctors and payers say they are waiting for outcomes data on the meds, from clinical trials expected to read out this year and next, before adopting the PCSK9 treatments more broadly. In an attempt to win payers over sooner, the companies they have set up performance-based deals with several insurers, which link rebates and discounts to the drugs' real-world cholesterol-lowering results. 

That has hurt sales. Analysts once predicted that Repatha and Praluent would bring in a combined $3 billion in sales by 2022. They have a long way to go: Sales of Repatha were $40 million in the third quarter of last year, while Praluent brought in just $38 million.

Damages have not yet been determined in the patent case. And Robinson has yet to decide whether to halt Praluent sales. If the case resolves with a royalty agreement instead, and sales pick up, Amgen could be in good shape. A year ago, investment bank Chardan predicted that Amgen would prevail in the case and receive 10% to 20% of Praluent’s sales.