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On June 4, 2026, the U.S. Supreme Court issued a unanimous decision in Hikma Pharmaceuticals USA Inc. v. Amarin Pharma, Inc., No. 24-889, holding that generic drug manufacturer Hikma did not “actively induce” infringement of Amarin’s cardiovascular method of use patents for Vascepa (icosapent ethyl) through its labeling, marketing materials, or press releases. This decision is significant because it clarifies what type of evidence is needed to prevail on an inducement claim against a generic drug manufacturer marketing a product with a so-called “Skinny Label” that carves out otherwise patented uses. In contrast to the Federal Circuit’s approach, which according to the Supreme Court had “increasingly trained its focus on whether the relevant statements could be read by medical providers as instructions to infringe,” the opinion refocuses the analysis on the conduct of the generic manufacturer, i.e., what the manufacturer is actually encouraging, rather than how downstream prescribers might interpret the labeling. [1] For branded companies, in particular, the decision places renewed emphasis on carefully considering the complex interplay of how patent claims are drafted in view of drug product indications pursued before the FDA.

Skinny Labels and Generic Drug Products

Under the Hatch-Waxman Act [2], a generic manufacturer can enter the market without repeating the extensive clinical trials required for new drug approval. The generic manufacturer can seek FDA approval through an Abbreviated New Drug Application (ANDA), relying on the branded product’s safety and efficacy data rather than conducting new clinical trials. When the FDA approves a brand-name drug, the original developer typically holds patents covering the drug active, formulations, and specific therapeutic uses. If some of the branded drug’s approved uses are still under patent, the generic manufacturer can file a “section viii statement,” seeking approval for only the unpatented uses. The resulting generic label, commonly referred to as a “Skinny Label,” excludes patented indications and permits marketing only for the remaining uses.

In theory, this type of generic drug labeling cleanly separates the patented from unpatented uses. In practice, this separation can become muddled. Because approved generics (in most instances) are considered therapeutically equivalent, physicians routinely prescribe and pharmacists routinely substitute them in place of the branded products, even though the generic label may not expressly cover the indication being prescribed for. However, this practical reality, standing alone, does not establish patent liability. Inducement of patent infringement requires more than awareness that a product may be used in an infringing manner; it turns on whether the manufacturer has taken affirmative steps to encourage that use.

The Dispute

Amarin’s drug Vascepa was first approved in 2012 for treating severe hypertriglyceridemia (the “SH indication”), with patent protection covering the composition of the active ingredient icosapent ethyl along with patents directed at the capsule dosage form and oral administration. In 2019, the FDA approved Vascepa for a second, more commercially significant use: reducing cardiovascular risk in patients already taking statins (the “CV indication”). Amarin obtained additional method of use patents for the CV indication that were first filed in 2012.

Hikma initially challenged the SH patents through a paragraph IV certification. As Amarin obtained new patents covering the CV indication, Hikma supplemented its pending application with a section viii statement and ultimately proceeded, after the SH patents were invalidated, with a skinny label limited to the unpatented SH indication. The FDA approved Hikma’s generic in 2020 and assigned it an “AB” rating, which means the U.S. Food and Drug Administration (FDA) classified it as therapeutically equivalent and fully interchangeable with the brand-name reference drug Vascepa. Amarin nevertheless sued, alleging that the totality of Hikma’s statements, including its label, patient leaflet, website, and press releases, actively induced infringement of the CV-indication patents.

The District Court dismissed the case at the pleading stage. The Federal Circuit revived it, finding it “at least plausible that a physician could read the relevant statements as an instruction or encouragement to infringe.” The “relevant statements” refer to the totality of Hikma’s communications at issue: the skinny label, the patient information leaflet, Hikma’s website, and its press releases. The Supreme Court reversed and reinstated the dismissal.

The Supreme Court’s Analysis

The Court reframed the inquiry. The question is not whether physicians could interpret a manufacturer’s statements as suggesting an infringing use. The question is “whether Amarin plausibly alleged that Hikma actively encouraged infringing use.”

Applying that framework, the Court found Amarin’s allegations insufficient on three grounds:

First, much of Hikma’s conduct had an obvious and lawful explanation. Generic labeling is governed by statute, which requires the label to mirror the branded product except for carved out uses. Describing a product as the “generic equivalent” of a branded drug is standard industry practice. The Court declined to treat compliance with regulatory requirements and industry practice as evidence of inducement.

Second, omissions are not active steps. Amarin pointed to what Hikma failed to say that it never warned its drug was not approved for the CV indication. The Court held that “mere omissions, inactions, or nonfeasance” cannot establish active inducement; otherwise, “ordinary merchants could become liable for any misuse of their goods and services, no matter how attenuated their relationship with the wrongdoer.”

Third, the remaining statements were too vague. References in patient materials to cardiovascular risks, general therapeutic descriptions on Hikma’s website, and press releases citing overall product sales required too many steps of inference to plausibly show an intent to encourage infringement.

The Court also clarified the governing legal standard. It declined Amarin’s invitation to import a “could be understood” standard from First Amendment coercion law, which would have weakened the inducement threshold. At the same time, it rejected Hikma’s assertion that inducement must be “express,” explaining that implicit encouragement can suffice so long as it is clear and affirmative to the relevant audience.

Strategic Takeaways

The “could be read” standard no longer drives inducement risk. The Supreme Court has drawn a clear line: liability for inducement requires evidence that a generic manufacturer affirmatively encouraged infringing use, not that a physician might independently draw that inference from standard marketing materials.

Skinny labels remain viable, but they are not the entire analysis. The ruling reinforces the continued viability of the section viii pathway. A properly crafted skinny label, standing alone, is unlikely to support an inducement claim. At the same time, the opinion makes clear that liability can still arise from conduct beyond the label if it amounts to clear encouragement of a patented use.

Lifecycle planning for follow-on indications. The timing of patent protection across multiple indications takes on added importance. Where earlier patents expire or are invalidated before later-issued method of use patents are firmly established, generics may be able to enter with a skinny label that captures a substantial portion of the market.

Align patent claims with FDA-approved indications. The decision highlights the importance of how closely patent claims track FDA-approved indications. Even where patent protection remains in place, differences between claim scope and label language can create opportunities for generic manufacturers to pursue skinny label approvals. When claims more precisely reflect the clinical parameters of an approved use, it becomes harder to carve out the patented indication while marketing a therapeutically equivalent substitute.

Concluding Thoughts

Hikma v. Amarin marks a significant recalibration of induced infringement pleading standards and ensures liability attaches when a generic manufacturer encourages infringing use. With this new analysis, the Supreme Court has balanced the preservation of the integrity of patent rights and the accessibility of lower cost generic medications.

[1] The Federal Circuit decision was based on both a specific prior ruling and a broader trend that the Supreme Court has rejected. The Supreme Court now says: “To Amarin’s credit, this argument reflects the recent approach of the Federal Circuit, which has increasingly trained its focus on whether the relevant statements could be read by medical providers as instructions to infringe. See, e.g., GlaxoSmithKline LLC v. Teva Pharmaceuticals USA, Inc., 7 F. 4th 1320, 1336–1337 (2021). The decision below appears to follow this trend line. See 104 F. 4th, at 1378–1380 (resting reversal on the conclusion that it is “at least plausible that a physician could read” the relevant statements “as an instruction or encouragement” to in­fringe). We reject that trend today, and hereby emphasize that the key question is whether a defendant actively encouraged infringement through its statements, not merely how others may understand those statements.”

[2] The Hatch-Waxman Act (formally, the Drug Price Competition and Patent Term Restoration Act of 1984, 21 U.S.C. § 355) is a federal statute that created a streamlined pathway for generic drugs to reach the market. Rather than repeating the brand-name manufacturer’s clinical trials, a generic company may submit an abbreviated new drug application, i.e. an ANDA, demonstrating that its product is bioequivalent to the branded drug and rely on the brand’s existing safety and efficacy data. At the same time, the Act provides certain regulatory marketing exclusivity provisions and preserves patent protections by requiring the FDA to maintain a public listing of certain patents covering approved drugs, known as the “Orange Book,” which has the full name: Approved Drug Products with Therapeutic Equivalence Evaluations. When applying for generic approval, a manufacturer generally has two options: 1) certify that the listed patents are invalid or will not be infringed, or 2) seek approval only for uses not protected by those patents. This latter pathway – often called a “Skinny Label” – reduces but does not eliminate potential patent-infringement exposure if the product is promoted in a manner that encourages the patented use.