Trimming the Fat: Supreme Court Slims Down Skinny Label Liability

Key Takeaways

• The United States Supreme Court narrowed skinny label induced infringement liability, holding that the branded manufacturer must plausibly allege that the generic manufacturer’s affirmative conduct actively encourages patent infringement to survive a motion to dismiss.
• Routine FDA labeling compliance and standard generic drug marketing practices generally do not establish induced infringement liability without additional evidence of active encouragement.
• The decision signals a generic-friendly shift in future skinny label patent ligation, where generics likely gain stronger defenses for early dismissal, while branded manufacturers will likely face a higher burden at the pleading stage.

On June 4, 2026, the United States Supreme Court issued its decision in Hikma Pharmaceuticals USA Inc. v. Amarin Pharma, Inc. In its decision, the Supreme Court reversed the Federal Circuit, and held that Amarin’s complaint failed to plausibly allege that Hikma’s skinny label generic induced infringement of Amarin’s patents under 35 U.S.C. §271(b).

The Supreme Court made clear that the relevant question on induced infringement is whether the generic manufacturer actively encouraged infringement, not whether healthcare providers could plausibly interpret the manufacturer’s statements or conduct as instructions to infringe. This decision is a significant win for generic manufacturers and raises the bar for branded manufacturers seeking to challenge generics approved via the Section VIII pathway of the Hatch-Waxman Act.

How the Hikma v. Amarin Skinny Label Case Reached the Supreme Court

In 2012, the FDA approved Amarin’s Vascepa (icosapent ethyl) as a treatment for severe hypertriglyceridemia (the “SH Indication”). In 2016, Hikma submitted an ANDA for approval of its generic icosapent ethyl via a Paragraph IV certification. Amarin sued Hikma, which resulted in Amarin’s method of-use patents for the SH Indication being invalidated.

Prior to the SH Indication method-use-of patents being invalidated, and while Hikma’s ANDA remained pending before the FDA, Vascepa was approved for an additional indication — as a treatment to reduce cardiovascular risk in statin-taking hypertriglyceridemia patients (the “CV Indication”). Amarin later obtained the two method-of-use patents for the CV Indication, which were at-issue in this case.

Following FDA approval for the CV Indication, Hikma supplemented its ANDA with a Section VIII statement and sought approval for a “skinny label” that carved out the CV Indication and included only the non-patented SH Indication. Hikma’s skinny label was subsequently approved by the FDA in 2020. Soon after Hikma began marketing its generic icosapent ethyl, Amarin filed suit in the District of Delaware alleging that Hikma induced infringement of Amarin’s method-of-use patents for the CV Indication under 35 U.S.C. §271(b) pointing to Hikma’s skinny label, patient leaflet, website statements, and press releases as evidence of active steps taken by Hikma that encouraged infringement.

The district court dismissed under Federal Rule of Civil Procedure 12(b)(6) for failure to state a plausible claim for induced infringement. The Federal Circuit reversed, concluding that it was at least plausible that physicians could read Hikma’s label, website, and press releases as instructions or encouragement to prescribe Hikma’s generic for a patented use.

The Supreme Court’s Decision

Justice Jackson, writing for a unanimous Court, held that Amarin failed to state a plausible claim for induced infringement under 35 U.S.C. §271(b). The Court emphasized that the central question is whether the defendant actively encouraged an infringing use, not merely whether a physician could read the defendant’s statements as instructions to infringe.

The Court identified three reasons why Amarin’s allegations fell short:

1. Legal/Industry Compliance as “Obvious Alternative Explanation” of Conduct

Several of Hikma’s statements — including retaining clinical study information on its label and describing its product as “generic Vascepa” — the Court said, reflected legal obligations (e.g., the “duty of sameness” under 21 U.S.C. §355(j)(2)(A)(v)) and normal industry practice, and were therefore “obvious alternative explanations” for Hikma’s conduct that could not give rise to inducement liability.

2. Omissions From a Skinny Label Are Not “Active Steps”

Active inducement requires affirmative conduct. Mere omissions, inactions, or nonfeasance, such as Hikma’s omission of a limitation of use for the CV Indication from its label and failure to clarify that its approved use was limited to the SH Indication in press releases. The Court found that omissions, inactions, or nonfeasance are insufficient to satisfy the “active steps” element required to establish inducement liability.

3. Vague Statements and Speculation Are Insufficient

The Court held that Hikma’s remaining statements that categorized the drug under “hypertriglyceridemia” on its website, noting an “AB” equivalence rating, warning of cardiovascular side effects in the patient leaflet, and touting aggregate sales figures of Vascepa in investor press releases were too vague, and, at most, described a possible chain of inferences, not a plausible one to support inducement liability.

Implications for Drug Manufacturers

Generic Manufacturers: skinny labels could have significantly more impact on the induced infringement analysis going forward, sometimes being dipositive at the motion to dismiss stage. Regulatory labeling compliance, normal industry practices, the use of standard therapeutic equivalence terminology, and other routine commercial statements may not, without more, give rise to induced infringement liability.

Branded Manufacturers: seeking to bring skinny label inducement claims may present additional challenges in the future. To survive the pleading stage, a complaint should allege plausible, affirmative conduct showing active encouragement of infringement, not just statements or conduct that could be interpreted that way. Branded manufacturers may want to revisit their patent claim strategy for method of use claims, aiming to best ensure that downstream uses can be plausibly alleged during litigation.

For further discussion on these issues or other similar inquiries, please contact AGG Intellectual Property partner Matt Zapadka or patent agent John Schneible.