Hikma v. Amarin: Supreme Court Examines Induced Infringement in the Context of Generic Drug Labeling

by Nafsika Karavida and Lucia Mead

Last month, the Supreme Court of the United States heard oral arguments in Hikma Pharmaceuticals USA Inc. v. Amarin Pharma, Inc., a landmark pharmaceutical patent dispute concerning whether a generic drug manufacturer may face liability for induced patent infringement after marketing a “skinny-label” generic that omits patented uses from its FDA-approved labeling.

The case focuses on the intersection of patent law and the Hatch-Waxman Act, the federal framework designed to balance pharmaceutical innovation with the availability of lower-cost generic medications. Under Hatch-Waxman, generic manufacturers may seek approval to market a generic version of a branded drug for uses that are no longer protected by patent while omitting patented indications from the drug’s labeling. For example, a company might make a generic version of a drug but only get approval to say it treats “high cholesterol,” because that use is not patented anymore. If the original drug is also patented for helping prevent heart attacks, the generic label cannot include that indication on its labeling, even though doctors could still prescribe it that way. This practice is commonly referred to as “skinny-labeling” or a “carve-out label.”[1]

In this case, Amarin Pharma, Inc. manufactured Vascepa, a drug originally approved for the treatment of severe hypertriglyceridemia, a medical condition characterized by abnormally elevated levels of triglycerides (fat) in the bloodstream. After Vascepa entered the market, Amarin then obtained additional patents covering a separate cardiovascular risk-reduction use for the drug. Those later patents remained in force, even after the original indication became open to generic competition. Hikma Pharmaceuticals USA Inc. later sought FDA approval to market a generic version of Vascepa. In an effort to avoid infringing Amarin’s cardiovascular patents, Hikma used a “skinny label” and requested approval only for the older, non-patented indication (i.e., for treating severe hypertriglyceridemia). The newer patented cardiovascular use was specifically omitted from Hikma’s proposed labeling.

Despite the carve-out, in August of 2020 Amarin filed suit in the U.S. District Court in Delaware alleging that Hikma encouraged physicians and pharmacists to prescribe the generic product for the patented cardiovascular use. According to Amarin, Hikma’s press releases, website language, and investor communications referred to the product as a “generic version” of Vascepa and discussed the broader Vascepa market in a manner that allegedly promoted off-label use covered by Amarin’s patents.[2] Hikma argued that its FDA-approved “skinny label” demonstrated an effort to comply with patent law and avoid promoting patented uses. Amarin, however, contended that the company’s broader communications and marketing activities effectively encouraged the patented use despite the carve-out label.

The district court initially dismissed Amarin’s claims, finding that Hikma’s conduct was insufficient to plausibly establish the intent required under the doctrine of induced infringement, which permits liability where a party actively encourages another to infringe a patent.[3] On appeal, however, the United States Court of Appeals for the Federal Circuit reversed the dismissal. The Federal Circuit concluded that the “totality of the circumstances,” including Hikma’s public statements and promotional materials viewed alongside the skinny label, was enough to allow the case to proceed.[4]

The Supreme Court’s decision to grant review has drawn significant attention across the pharmaceutical industry, as it will clarify the scope of liability for induced infringement in the context of “skinny label” generic drug products. The Court’s interpretation of the intent standard may affect how confidently generic manufacturers can rely on FDA-approved carve-outs when launching lower-cost alternatives.

If the Court adopts a broader theory of induced infringement, generic manufacturers may face increased litigation exposure even where they have complied with FDA labeling requirements designed to omit patented indications. That added uncertainty could discourage or delay generic entry in some cases, particularly where manufacturers perceive a heightened risk of post-launch patent litigation tied to marketing language or public statements. Over time, reduced or delayed generic competition may place upward pressure on drug prices by limiting the speed at which lower-cost alternatives enter the market after patent protection narrows or expires for certain uses.

By contrast, a narrower standard would reinforce the Hatch-Waxman framework’s role in facilitating earlier generic competition through carve-out labeling. It would also provide clearer boundaries for permissible marketing and communications by generic manufacturers, reducing litigation risk and supporting more predictable pathways to market entry. For branded pharmaceutical manufacturers, however, this case could potentially strengthen the practical value of method-of-use patents, particularly in therapeutic areas where off-label prescribing is common. Because physicians are generally permitted to prescribe drugs for unapproved uses, innovators argue that carve-out labeling alone may not fully prevent erosion of patented indications in practice.

The practical stakes of these disputes are heightened by state generic substitution laws, many of which either permit or require pharmacists to dispense FDA-approved generic equivalents in place of brand-name drugs unless the prescribing physician specifically directs otherwise through a “dispense as written” instruction or similar designation. As a result, even where a generic manufacturer markets a product using a carve-out label that omits patented indications, the generic drug may still be substituted at the pharmacy counter for prescriptions written for the branded product.

More broadly, the Court’s ruling may affect drug pricing by slowing or discouraging generic entry, which can keep prices for brand-name drugs higher for longer. It may also influence how pharmaceutical companies plan the full life of a drug, including how they write labels, communicate about their products, and obtain additional patents for new uses of the same medication.

As the industry awaits the Court’s decision, Hikma Pharmaceuticals USA Inc. v. Amarin Pharma, Inc. remains a key case with significant implications for pharmaceutical competition, regulatory strategy, and drug affordability.

[1] Drug Price Competition and Patent Term Restoration Act of 1984 (Hatch-Waxman Act), Pub. L. No. 98-417, 98 Stat. 1585 (codified as amended in scattered sections of 15, 21, 28, and 35 U.S.C.); 21 U.S.C. § 355(j)(2)(A)(viii) (2022).

[2] Hikma Pharms. USA Inc. v. Amarin Pharma, Inc., 104 F.4th 1370, 1375–79 (Fed. Cir. 2024).

[3] Amarin Pharma, Inc. v. Hikma Pharms. USA Inc., No. 20-1630, 2021 WL 1171669, at *7-9 (D. Del. Mar. 29, 2021).

[4] Hikma Pharms., 104 F.4th at 1381-84.

This article is intended as a general discussion of these issues only and is not to be considered legal advice or relied upon. For more information, please contact RPJ Special Counsel Nafsika Karavida who counsels clients on employment, intellectual property, corporate and transactional, and cross-border commercial law. Ms. Karavida is admitted to practice law in Connecticut, New York, Sweden, the European Union, and before the United States Patent and Trademark Office.