Amgen loses appeal in patent suit against Sanofi/Regeneron’s Praluent. It’s a bummer for Bristol Myers Squibb and Merck, too

In a coda to a six-year legal fight on the PCSK9 terrain, the US Federal Court of Appeals has ruled that Amgen’s patent claims for PCSK9 antibodies as a class are invalid, handing a win to Sanofi and Regeneron.

The implications, though, may reverberate far beyond Amgen.

The Thousand Oaks, CA-based company, whose Repatha was approved a month after Praluent in 2015, may take comfort in the fact that its sales have consistently eclipsed Sanofi or Regeneron’s, although neither has climbed anywhere near the blockbuster expectations developers and analysts had.

Amgen first took Sanofi and Regeneron to court before those drugs went on the market, seeking to block the sale of Praluent. While a jury and a judge have previously sided with Amgen — going so far as to grant an injunction against Sanofi and Regeneron (a stay was soon issued) — in late 2019, a US judge overturned that verdict and ruled in favor of the heavyweight drug partners. It was a bitter loss for Amgen’s famously aggressive lawyer corps, which has scored high-profile victories such as the megablockbuster case against Novartis’ generics arm Sandoz.

That decision, by the US District Court in Delaware, was upheld in the Court of Appeals for the Federal Circuit.

Joseph LaRosa, EVP, general counsel and secretary at Regeneron, said the ruling helps to “provide closure” on the patent issue now that they have fended off all five of Amgen’s asserted claims against Praluent.

But in an amicus brief filed in March, Bristol Myers Squibb and Merck suggested it sends an unwelcome message not just for Amgen but other “innovator companies” who care about patent protection.

The toughest part of creating a successful antibody drug, they argued, is to find the right target and application; once those are identified, “it is easy to create variations.” From the filing:

The patentee, having invested enormous sums in discovering the underlying target, has provided a blueprint for others who, now aware of the targets, can quickly make their own version of an effective antibody. The scope of the invention in this space is therefore the genus of antibodies that successfully binds the target, rather than any particular antibody that serves as an example. […]

The Court’s conclusion ignores the involved time, effort, and creativity that it took the inventors to come up with the concept in the first place, to test it again and again to make sure it is robust, and then to provide their roadmap to the world.