When does a generic drug’s “skinny label” cross the line into skinny label patent infringement? For years the answer splintered the lower courts, and the Supreme Court has now resolved it.

Infringement of a patent does not always need to be direct; in fact, inducing someone else to directly infringe a patent can be enough to establish liability. On June 4, 2026, the Supreme Court addressed the scope of what constitutes induced infringement while responding to an appeal from the Federal Circuit, which reversed a grant of a motion to dismiss a claim for patent infringement from the District of Delaware.

Hikma Pharmaceuticals USA Inc. (Hikma) is a generic drug manufacturer and, in accordance with FDA guidelines, submitted an abbreviated new drug application (ANDA) in 2016, demonstrating that its drug is the biological equivalent of Vascepa. Because the FDA cannot approve a generic drug that would infringe a patent, Hikma filed a Paragraph IV certification with its ANDA, which states that a patent “is invalid or will not be infringed by the manufacture, use, or sale of the [generic] drug,” alleging that Amarin’s SH indication method-of-use patents are invalid. The Court explained that under 35 U.S.C. § 271(e)(2)(A), filing an abbreviated new drug application under section 505(j) of the FDA Act (codified at 21 U.S.C. § 355(j)) paragraph IV certification constitutes an act of infringement and therefore gives the patent holder the opportunity to “determine the validity and scope of the patent,” by suing the infringing party. Accordingly, Amarin sued Hikma for infringing its SH indication method-of-use patents, and the District of Nevada invalidated the asserted patent claims as obvious under 35 U.S.C. § 103.

Background

Amarin Pharma, Inc. (Amarin) developed a drug called Vascepa, which the FDA approved for treatment of severe hypertriglyceridemia (the “SH indication”) in 2012; Amarin had method-of-use patents for this indication. In 2019, the FDA approved the drug for another, more common use, to reduce “cardiovascular risk in hypertriglyceridemia patients who already take statins (the ‘CV indication’).” Amarin obtained two method-of-use patents for the CV indication.

Hikma later amended its ANDA with a Section VIII statement, which states that “the generic manufacturer will market the drug for one or more methods of use not covered by the brand’s patents.” Hikma proposed a skinny label that included only the SH indication for its generic drug (since Amarin’s SH indication patents were no longer valid) and excluded the still-patented CV indication. The FDA approved Hikma’s skinny label and assigned the generic drug an AB rating, indicating that it is therapeutically equivalent to Vascepa when used in accordance with its labeling.

Shortly after the generic drug was on the market, Amarin sued Hikma in the District of Delaware, alleging that Hikma actively induced others to infringe Amarin’s CV indication method-of-use patents through the following means:

Hikma’s skinny label did not include a CV Limitation of Use (meaning that the label did not expressly state that the drug was not to be used for the CV indication) and included information about a clinical study where some patients were taking statins;
The patient information leaflet that comes with the label warned consumers about potential side effects for “people who have heart (cardiovascular) disease,” which is the same target consumer for Vascepa’s CV indication method-of-use, and stated, “[m]edicines are sometimes prescribed for purposes other than those listed in a Patient Information leaflet”;
Hikma’s website included its generic drug’s AB rating and listed hypertriglyceridemia as the drug’s therapeutic category, which includes the SH indication, but is also broader than that; and
Hikma’s pre-launch press releases described the product as “generic Vascepa,” and did not mention that the generic drug’s use was only limited to the SH indication. The press releases also included sales figures from Amarin’s drug, which included both the SH and CV indication.

The district court dismissed Amarin’s suit, ruling that Hikma took no active steps to induce others to infringe the CV indication method-of-use patents. The Federal Circuit reversed the district court’s decision, reasoning that it was “at least plausible that a physician could read” Hikma’s label, website, and press release as an encouragement to prescribe the generic drug for all approved uses of icosapent ethyl (the active ingredient of Vascepa and the generic drug), including the CV indication. The Supreme Court granted certiorari to decide if Amarin’s suit could survive Hikma’s 12(b)(6) motion to dismiss.

Requirements For Active Inducement of Infringement Liability

The Supreme Court outlined three elements that must be satisfied for a party to be liable for induced infringement under 35 U.S.C. § 271(b):

There must be direct infringement by a third party;
The inducer must know the induced acts constitute patent infringement; and
The inducer must take active steps to encourage the direct infringement by the third party.

The third element, the requirement of “active steps,” was the issue at hand for the Supreme Court.

Defining Active Steps

The Supreme Court defined “active steps” to induce infringement as “‘the taking of affirmative,’ as opposed to passive, ‘steps to bring about the desired result’ of patent infringement.” The Court stated that to ensure regular commerce is not trenched on “‘ordinary acts incident to product distribution’ are insufficient to support liability.” The Court reasoned that without this rule, “ordinary merchants could become liable for any misuse of their goods and services, no matter how attenuated their relationship with the wrongdoer.” Further, the Court highlighted how “vague” language, when accompanied by speculation about how a third party may act, is insufficient to support a claim of inducement. Finally, the Court clarified that active inducement does not necessarily require express inducement; inducement can also be in the form of implicit encouragement.

Required Pleading Standard to Survive a Motion to Dismiss

The Supreme Court stated that the Federal Circuit was mistaken in its assessment that the fact that it was “‘at least plausible that a physician could read’ the relevant statements ‘as an instruction or encouragement to’ infringe,” was sufficient to survive a motion to dismiss. The Supreme Court clarified that the standard for overcoming a 12(b)(6) motion to dismiss is not whether medical providers could plausibly interpret Hikma’s statements as encouraging infringement, but whether “Amarin plausibly alleged that Hikma actively encouraged infringing uses.”

Skinny Label Patent Infringement: The Label and Press Releases

The Court, addressing whether the generic drug’s skinny label induced infringement through its lack of a CV Limitation of Use notice and inclusion of clinical studies including consumers taking statins, ruled that it did not.

The Court explained that by law, Hikma’s label, as a generic drug, must be identical to Amarin’s (with the exception of Amarin’s CV indication method-of-use). Therefore, because Amarin’s label did not include the CV Limitation of Use and included the clinical studies, Hikma was forced to do the same and could not be liable.

Further, the Court ruled that Hikma’s description of its generic drug as a “generic Vascepa” in its press releases also did not constitute inducement. The Court reasoned that it is normal industry practice for a generic drug to describe itself as an equivalent to a name brand, and the Court would not “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.”

Additionally, the Court reasoned that Hikma’s omission of a CV Limitation of Use on its label and notice that its drug was only approved for the SH indication in its press releases could not be sufficient to establish inducement, regardless of whether some medical providers mistakenly read this to be an encouragement to infringe Amarin’s patents, because “we look for affirmative “statements or actions” precisely to avoid “trenching on regular commerce” based on such a contingent chain of events.”

Overall, the Court found that the skinny label and press releases did not constitute “active steps” toward inducing infringement.

Leaflet and the Website

The Court also stated that the leaflet that lists possible side effects for people with cardiovascular diseases and states that medication is sometimes prescribed for uses other than those the drug specifically indicates is not sufficient to establish inducement. The Court reasoned that even if medical providers plausibly read this notice as an encouragement for infringing uses, Hikma did not “actively” induce them, and therefore Hikma’s creation of the leaflet did not “plausibly constitute [an] ‘affirmative step[] to bring about the desired result’ of infringement.”

The Court also ruled that Hikma’s listing of “hypertriglyceridemia” as the drug’s therapeutic category, and its AB rating on its website, are not active steps to encourage inducement. The Court reasoned that describing the generic drug’s therapeutic category as “hypertriglyceridemia,” rather than “severe hypertriglyceridemia,” is akin to describing a drug to treat leukemia as a “cancer drug,” rather than a “leukemia drug,” in that “cancer drug,” and “hypertriglyceridemia drug” are both broad categories of drugs, not “an instruction to prescribe the drug for a patented use treating a specific type of [illness].” Additionally, the Court stated that the AB rating listed on Hikma’s website means that the product is equivalent to the brand-name drug when used only per the conditions on the generic brand label, which excludes any patented methods of use. Therefore, Hikma was not encouraging its drug to be used for the CV indication. Finally, the Court reasoned that despite all of that, “Hikma’s website clarifies that ‘Hikma’s generic version is indicated for fewer than all approved indications of the Reference Listed Drug,’” and therefore did not encourage infringement.

Sales Figures

Finally, the Court ruled that Amarin’s sales figures that were included in Hikma’s press releases are the “vaguest of ‘vague’ statements in Amarin’s complaint,” and did not induce infringement. The Court reasoned that the chain connecting the inclusion of both the SH and CV sales data and medical providers infringing on Amarin’s patents is far too attenuated in that,

A medical provider would have to look up and read the press releases, which were directed to investors rather than doctors and pharmacists; have enough background knowledge of pharmaceutical sales to understand the quoted sales figures to be attributable to both the SH-indication and the CV-indication methods of use; and draw from this fact a subtle encouragement to start prescribing Hikma’s generic [drug] to hypertriglyceridemia patients who already take statins.

The Court stated that while anything is possible, this is not a “plausible” scenario of active inducement.

The Court concluded that Hikma had not taken any “active steps” to induce infringement of Amarin’s CV method-of-use patents. Therefore, Hikma’s motion to dismiss should have been granted. The Supreme Court reversed the Federal Circuit’s judgment and remanded the case for further proceedings consistent with its opinion.

Key Takeaways

To be liable for induced infringement, a party must take “affirmative steps” to encourage infringement, rather than just passive actions.
Ordinary acts incident to product distribution are insufficient for liability. Courts look for specific “statements or actions” that actively encourage infringement to avoid interfering with regular commerce.
A plaintiff must plausibly allege that a defendant actively encouraged infringing uses, not just that a third party could plausibly interpret statements as encouragement.
A generic manufacturer cannot be held liable for induced infringement for following legal requirements, such as maintaining a “skinny label” that is identical to the reference drug’s label (excluding the patented method of use).
Describing a generic drug as a “generic” version of a brand-name drug is standard industry practice and does not constitute inducement

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Hikma Pharmaceuticals USA Inc. v. Amarin Pharma, Inc.: The Supreme Court Clarifies Skinny Label Patent Infringement and Active Inducement