The decision clarifies that the relevant inquiry is whether a defendant actively encouraged infringing use, not merely whether physicians could plausibly read the defendant’s statements related to a skinny label as instructions to infringe.

Recently, the Supreme Court of the United States unanimously reversed the Federal Circuit in Hikma Pharmaceuticals USA Inc. v. Amarin Pharma, Inc. (No. 24-889), holding that Amarin failed to state a claim for active inducement of patent infringement under 35 U.S.C. § 271(b). The decision clarifies that the relevant inquiry is whether a defendant actively encouraged infringing use, not merely whether physicians could plausibly read the defendant’s statements related to a skinny label as instructions to infringe.

Amarin’s Vascepa (icosapent ethyl) is approved for treating severe hypertriglyceridemia (SH indication) with a blood triglyceride at least 500 mg/dL and cardiovascular risk reduction (CV indication) for a patient having a blood triglyceride at least 150 mg/dL. Hikma obtained ANDA approval and launched its generic with a section viii carveout omitting the patented CV indication, limiting its labeling to the SH indication. Amarin sued Hikma for induced infringement and argued that Hikma’s label and public statements—including its website, press releases and patient information leaflet—instructed physicians to use the generic product for the patented indication. The District Court of Delaware dismissed the inducement claims at the pleadings stage. In 2024, the Federal Circuit reversed, holding that the complaint plausibly pled inducement when the label was evaluated alongside the alleged nonlabel materials, allowing the case to proceed. The Supreme Court has now reversed and remanded.

Section viii, 21 U.S.C. § 355(j)(2)(A)(viii), authorizes FDA to approve generic labels that carve out patented methods. Separately, 35 U.S.C. § 271(b) imposes liability for inducement. Based on case laws, induced infringement requires “active steps” to encourage direct infringement—defined as “purposeful, culpable expression and conduct” that is “affirmative” rather than passive. In applying these standards, the Court analyzed Amarin’s allegations in three categories.

First, the Court states that several of Hikma’s statements had an “obvious alternative explanation”: compliance with the law or standard industry practice by using a skinny label. The Court also states that describing a product as “generic equivalent” is “normal industry practice.”

Second, the Court noted that “mere omissions, inactions, or nonfeasance”—such as omitting the CV limitation of use from the label or failing to clarify that Hikma’s approved use was limited to the SH indication—cannot support active inducement, and the Court looks for affirmative statements or actions.

Third, according to the Court, the remaining vague statements and speculation about how physicians may act do not support inducement liability. For example, the Court notes that the patient information leaflet’s warning about cardiovascular side effects and disclaimer related to prescription for unlisted purposes were “implausibly roundabout ways to induce” and the website’s description of the therapeutic category as “hypertriglyceridemia” and the “AB” rating are not designed to stimulate physicians to commit infringement. The Court points out that 35 U.S.C. § 271(b) requires active, not passive, inducement.

Notably, in a footnote, the Court rejected the Federal Circuit’s trend of focusing on whether statements “could be read” by physicians as encouragement, emphasizing instead that “the key question is whether a defendant actively encouraged infringement through its statements, not merely how others may understand those statements.” The Court acknowledged that this trend included the Federal Circuit’s GSK v. Teva line of decisions, but the Court did not engage with the substance of those rulings or address the broader analytical framework developed in the Federal Circuit’s ANDA-specific case law.

It is worthwhile to note that the Court grounded its inducement analysis in general patent and copyright precedent—Grokster, Global-Tech, Limelight Networks and even the recent Cox Communications decision—rather than the Federal Circuit’s ANDA-specific body of law. The opinion’s only reference to the GSK v. Teva precedent appears in a footnote rejecting the Federal Circuit’s “could be read” approach, without addressing the broader analytical considerations that the Federal Circuit developed in the skinny-label context over the past decade. The Court focuses on the standard for induced infringement and answered the specific question whether Amarin’s allegations meet the pleading standard. However, the Court does not directly address the questions related to the skinny label practice.

For brand manufacturers, the decision narrows the evidentiary path for pleading inducement: Allegations must identify affirmative conduct designed to encourage the patented use, rather than relying on omissions, vague statements or speculative chains of inference. For generics, this ruling reinforces that a compliant skinny label, combined with standard industry descriptions and ordinary acts incident to product distribution, does not give rise to inducement liability. However, the opinion does not create an absolute safe harbor. The Court left open the possibility that inducement could be established through clear and affirmative encouragement—whether express or implicit—so long as it is “designed to stimulate others to commit” infringement. Considering the case law from both the Supreme Court and the Federal Circuit, generic manufacturers should nonetheless continue to perform technical and legal analyses before using a skinny label.

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