Supreme Court Protects ‘Skinny Label’ Generic Drug Pathway (2)

The US Supreme Court raised the bar for branded pharmaceutical companies seeking to sue over a competitor’s generic versions of their drugs that are marketed using what’s called a skinny label.

The justices unanimously concluded that a district court judge was right to dismiss Amarin Pharma Inc.'s infringement suit over claims that Hikma Pharmaceuticals USA Inc. was encouraging doctors to prescribe its generic version of Amarin’s Vascepa heart health drug for a still-patented treatment method.

Drugmakers frequently obtain patents not just on chemical compounds they discover for novel drugs, but separately for methods of using such drugs to treat various medical conditions. When some uses are covered by active patents while others aren’t, generics can get government approval of a “skinny label” that carves out the patented uses.

Thursday’s ruling ramps up the evidence that branded drugmakers need in order to sue when they think the generic label in combination with a generic company’s marketing statements or other communications cross a line into actively inducing patent infringement.

Amarin said Hikma had encouraged doctors to prescribe its generic for reducing cardiovascular risk—a still-patented use. The company pointed to language Hikma used in a part of its label that described potential side effects; Hikma’s failure to affirmatively warn against prescribing for the still-patented uses of the drug in its label and in press releases; statements to potential investors; and references in Hikma press releases that described its product as “generic Vascepa” or the “generic equivalent” of Vascepa.

“Our case law leaves generic manufacturers more breathing room than that,” wrote Justice Ketanji Brown Jackson for a unanimous court.

Active Encouragement Key

Amarin sued Hikma in 2020 in the US District Court for the District of Delaware shortly after the latter began marketing a generic version of Vascepa with a skinny label approved by the US Food and Drug Administration. The label described using the drug—a fish oil derivative—to treat severe hypertriglyceridemia and carves out mentions of using the drug to treat cardiovascular risk.

The US Court of Appeals for the Federal Circuit reversed the district judge’s dismissal, but Jackson said the appeals court applied the wrong test for evaluating induced infringement.

“The central question is whether Amarin plausibly alleged that Hikma actively encouraged infringing uses, not merely whether doctors could plausibly read the alleged statements as instructions to infringe,” she wrote.

“All in all, inducement cannot be based only on ‘vague’ language” combined with “speculation” about how others might act, she said.

Still, the high court rejected Hikma’s invitation to broadly immunize skinny label drugs when it comes to induced infringement liability by requiring a potential plaintiff to produce evidence showing a defendant expressly told a third party to infringe a patent.

“A defendant can achieve active inducement through implict encouragement,” Jackson wrote. “But implicit or explicit, the necessary inducement must be ‘clear’ to the relevant audience and ‘affirmative.’”

‘Sigh of Relief’

Several attorneys who work in the pharma patent space said the ruling wasn’t earth-shattering, but would give generic companies more leeway in communicating with investors.

“There’s a fundamental tension in wanting to announce your business successes in the broadest terms possible and to the largest audiences possible” and from a legal perspective where in-house counsel want to speak “more cautiously,” said Jeremiah Helm, a partner at Knobbe Martens, which frequently represents generic pharmaceutical companies.

The ruling makes it easier for generic manufacturers to talk to investors “as long as you’re not actively trying to get that info to the people who might infringe in a way that’s trying to get them to infringe,” he said.

“This is not the end of induced infringement claims against generics,” said Deepro Mukerjee, a partner at Katten Muchin Rosenman who primarily represents generic companies. “But I do think it signals courts should require concrete allegations of encouragement—it can’t just be allegations a generic maker participated in a market where off-label prescribing predictably occurs.”

Chris Loh, a Venable partner who represents branded drug companies, said the court appeared motivated by a concern that the Federal Circuit’s approach to skinny label inducement cases was punishing companies for a few very specific types of speech—a generic company describing its product as “equivalent” or “AB"-rated—another way to say a drug is therapeutically equivalent when used according to its label.

The opinion says that form of liability “put generic manufacturers between a rock and a hard place by turning adherence to the law and industry standards into building blocks for illegal conduct.”

But “beyond that, who knows?” Loh said. The ruling was “pretty fact bound” with “no sweeping statement about immunity for skinny-label drugmakers,” and so other types of generic marketing statements could still lead to liability, he said.

Still, Chad Landmon, who chairs Polsinelli’s Hatch-Waxman & Biologics practice, said the decision “will certainly be a sigh of relief for the generic drug industry and will support the continued use of skinny labeling to avoid infringement of method of use patents.”

Winston & Strawn represents Hikma. Amarin is represented by Perkins Coie.

The case is Hikma Pharms. USA Inc. v. Amarin Pharma, Inc., 2026 BL 207741, U.S., No. 24-889, 6/4/26.