Bloomberg Law
April 18, 2022, 1:44 PM

Amgen Cholesterol Patent Fight Needs DOJ’s Take, Justices Say

Samantha Handler
Samantha Handler

The U.S. Supreme Court on Monday asked the solicitor general to weigh in on Amgen Inc.'s long-running dispute with Sanofi and Regeneron Pharmaceuticals Inc. over the fate of its cholesterol drug patents.

The U.S. Court of Appeals for the Federal Circuit found in February 2021 that Amgen’s patents on Repatha that covered hundreds of distinct antibodies were too broad to be valid, ruling that a skilled expert wouldn’t be able to recreate all possible variations of the invention without undue experimentation.

Amgen argued that the Federal Circuit’s holding “defies more than a century” of high court precedent and would have a “devastating” impact on innovation. Amgen had sued Sanofi, alleging its competing drug Praluent infringed Amgen’s Repatha patents. Amgen’s patents are related to a genus of antibodies called PCSK9, which help patients control their cholesterol where widely used statins have failed.

Two Delaware juries upheld the patents, but a trial judge later found that the patents never should have been granted because of the time and effort it would take to recreate the invention. The requirement ensures that inventions are described well enough in patent claims that they can be made and used. An invention is invalid if it can’t be recreated by an expert in the field.

The Federal Circuit’s ruling that the requirement is a question of law for a judge to decide and not a question of fact for a jury conflicts with precedent, Amgen argued. The appeals court also expanded the requirement to include a test that skilled artisans must be able to cumulatively identify or make nearly all possible variations of the invention without substantial time and effort, Amgen said, warning that such a restriction could deter innovation in the biotech and pharmaceutical industries.

Sanofi argued in its brief that the Federal Circuit’s treatment of the enablement requirement in this case is consistent with Supreme Court precedent and no “special test” was created.

“Amgen also vastly overstates the importance of this issue,” Sanofi argued. “By Amgen’s own telling, the Federal Circuit’s purported ‘rule’ has been in place without modification since 1983.”

MoloLamken LLP represents Amgen. Kirkland & Ellis LLP represents Sanofi.

The case is Amgen, Inc. v. Sanofi, U.S., No. 21-757, solicitor general brief requested 4/18/22.

To contact the reporter on this story: Samantha Handler in Washington at

To contact the editors responsible for this story: Martha Mueller Neff at; Jay-Anne B. Casuga at