In Amgen-Sanofi Decision, High Court Sticks to Patent Law Script

The US Supreme Court’s decision in a fight over two Amgen Inc. patents affirmed the narrow scope of a patent law requirement known as enablement, allowing more pharmaceutical companies to keep competing in the same areas of research and development.

The high court sided with Sanofi and Regeneron Pharmaceuticals Inc. in their dispute with Amgen over cholesterol drugs by adhering to a strict reading of US patent law and clarifying how specific a patent must be to be valid.

The ruling makes it harder for a single company to monopolize one area of research through a broadly defined patent. It also casts a shadow on a research technique known as conservative substitution, under which Amgen laid claim to a larger pool of antibodies.

“For the last decade, justices have been largely focused on procedural issues in patent law. With today’s unanimous decision, the court turned to core, substantive patent law,” said Robin Feldman, a law professor at the University of California College of Law, San Francisco, formerly known as UC Hastings. “I see this as an important moment in recent Supreme Court jurisprudence.”

New Tech, Same Rules

The justices upheld a lower court ruling invalidating two Amgen patents covering its drug Repatha, which reduces LDL (“bad”) cholesterol levels. The opinion by Justice Neil Gorsuch cemented decades of precedent around the patent enablement standard laid out in the Patent Act.

Under the standard, patent applications must contain enough information about a claimed invention to enable someone with expertise in the field to make and use it. The decision left intact the US Court of Appeals for the Federal Circuit’s interpretations of that statute, including that the claims can’t require “undue experimentation” to reach the patented concept.

“The decision demonstrated a deep respect for patent law and for carefully hewing to the words of the legislation,” Feldman said.

Antibody patents of the sort at issue in the case cover some of drugmakers’ most valuable properties, including blockbuster treatments like AbbVie Inc.‘s Humira and Merck & Co.‘s Keytruda. When such treatments first emerged in the 1990s, the US Patent and Trademark Office was more permissive of broad patent claims that protected a whole category of antibodies that could perform a listed function, said Christopher Cowles, an IP partner at Withersworldwide.

Thursday’s decision corrects this “glaring outlier,” Cowles said. He noted that it “makes sense to harmonize the rest of biology with the antibody space.”

The justices cited cases decided between 1854 and 1928 that lay out how the enablement standard should work, ranging in subject matter from Samuel Morse’s telegraph patent to a patent on an electric lamp asserted against Thomas Edison.

“While the technologies in these older cases may seem a world away from the antibody treatments of today, the decisions are no less instructive for it,” Gorsuch wrote.

Will Milliken, co-chair of Sterne, Kessler, Goldstein & Fox PLLC’s appellate practice, said the court reiterated that patent law should be applied consistently across inventions.

“This suggests that, in the Court’s view, the same enablement analysis applies to all patents, no matter the technology—antibody patents are not special,” Milliken wrote in an email to Bloomberg Law.

Patent Scope

The justices left room for drug companies to offer examples of what their patent covers without listing out every antibody—but only to a certain extent. They foreshadowed that approach during oral argument in March, with extensive discussion of how many possible antibodies Amgen’s claims could’ve covered, Dorsey & Whitney LLP’s Matt Jonsen, who specializes in biotech and chemical patents, said in an email.

Justices Clarence Thomas and Ketanji Brown Jackson zeroed in during the argument on the 384 antibodies identified in the patents that bind to the “sweet spot” of proteins called PCSK9 inhibitors, as well as specific amino acid sequences that the patents identify for 26 of those antibodies.

Aside from these examples, Amgen claimed that any sequence that has the same effect of blocking LDL receptors within this category should also be protected using what’s known as functional genus claims. Sanofi and Regeneron had asserted that this could amount to millions of possible antibody combinations, and Amgen’s witnesses didn’t disagree.

“So in other words, you can’t say how many?” Thomas asked Amgen’s counsel.

That discussion was “fatal” for Amgen, Jonsen said.

“If 300 or even 400 was the extent of the genus, the Supreme Court may have ruled in their favor,” Jonsen said. “But when Amgen was forced to defend a scope of millions, the tenor was changed and the justices appeared unable to get past that number.”

Development Effects

The practical effects of the ruling, including whether it will encourage more research and development and lower drug prices, remain to be seen.

The decision signals that rivals theoretically are free to make new discoveries in a research area that another company pioneered first, Jonsen said. For competitors, that lessens the “fear of being hit with an infringement lawsuit,” he said.

“For biotech companies with first-in-class antibody intellectual property—they’ve lost the ability to threaten competitors that get too close to their IP,” Jonsen said. “The Supreme Court has significantly de-risked many projects.”

In the short term, practitioners are seen as likely to file longer drug patent applications that include lengthy tables of the sequences they intend to cover. That approach doesn’t foreclose “prophetic efforts” that list potentially successful combinations, Cowles said, but they will still focus on enumerating what specifically the patent covers.

Jonsen agreed that inventors will be encouraged to draft claims “focused on concrete examples, to avoid invalidation of all claims.”

In the wake of the decision, inventors should also be wary of relying on what’s known as conservative amino acid substitutions, which are modest variations in antibody combinations, said Kevin E. Noonan, co-chair of McDonnell Boehnen Hulbert & Berghoff LLP’s Biotechnology and Pharmaceuticals Practice Group.

Such substitutions were generally presumed to be covered by patent applications, but that convention has “been rebutted or thrown into grave doubt” by Amgen’s loss, Noonan said.

The case is Amgen Inc., et al., Petitioners vs. Sanofi, et al., U.S., No. 21-757, affirmed 5/18/23.