After Hikma: A Transatlantic View Of Skinny Labels And Pharma Strategy

By Carla J. Baumel, Ellen K. Levish, Kai Rüting, and Sarah Taylor

For decades, generic drug manufacturers have relied on the Hatch-Waxman Act’s “skinny label” pathway to enter the market by seeking approval only for a subset of indications, leaving more durably patented uses off the generic drug’s FDA-approved label. In the U.S., an AB-rated generic often can be substituted at the pharmacy for the patent-protected drug, even if the original prescription was for a patented indication that the generic is not approved or labelled to treat. Substitution is based on the identity of the drug, not the indication. 

The Federal Circuit’s 2024 decision in Hikma Pharmaceuticals USA Inc. v. Amarin Pharma, Inc., however, unsettled this long-standing paradigm. The Federal Circuit suggested a generic might induce patent infringement merely by obtaining and publicizing the AB rating with knowledge that the drug might be substituted for a patented indication. Generics faced the risk that they could be forced into expensive patent litigation when merely following the regulatory roadmap for a permitted label carve-out.

The Supreme Court has now largely put that uncertainty to rest. In a unanimous decision issued on June 4, 2026, the Court reversed the Federal Circuit and reaffirmed that induced infringement requires affirmative conduct encouraging the patented use. Merely complying with FDA requirements or describing a drug as a generic equivalent is not enough.

While the Supreme Court’s holding is narrow in some respects, its practical implications are broad. Against the backdrop of fragmented approaches to skinny labelling across Europe, including in the U.K., Hikma underscores the difficult balance generic manufacturers must strike when seeking to enter the market.  The decision is likely to influence how and where follow-on manufacturers select launch opportunities, how brand companies think about patents on new indications, and how both sides approach labeling, marketing, and litigation.

What The Supreme Court Clarified

The underlying Hikma dispute involved icosapent ethyl, marketed by Amarin as Vascepta. Vascepa received FDA-approved indications for treating severe hypertriglyceridemia and for reducing cardiovascular risk in certain patients. Hikma sought approval for a generic version for the unpatented hypertriglyceridemia indication and carved the patented cardiovascular indication out of its proposed label.

Amarin nevertheless alleged that Hikma induced infringement of its cardiovascular-use patents. It pointed to statements describing the generic as AB-rated and broadly directed to cardiovascular patients in Hikma’s label, patient information, website, and press releases, arguing that physicians could understand those materials as encouraging use of Hikma’s product for the patented cardiovascular indication.

The Supreme Court rejected that theory. The Court focused instead on whether the manufacturer itself took active steps to encourage the patented use, rather than whether a physician could interpret the manufacturer’s statements in a way that led to infringement.

Much of the conduct Amarin challenged, however, reflected regulatory requirements or ordinary industry practice. Generic manufacturers generally must maintain labeling that is the same as the brand’s labeling, except for the carved-out use. Likewise, terms such as “generic equivalent” and “AB-rated” are common and accurate ways to describe an approved generic product. The Court declined to turn compliance with those requirements and industry conventions into evidence of active encouragement to treat the patented indication.

The Supreme Court summarized: “All in all, inducement cannot be based only on ‘vague’ language ‘combined with speculation about how [others] may act.’ . . . A defendant can achieve active inducement through implicit encouragement, [b]ut implicit or explicit, the necessary inducement must be ‘clear’ to the relevant audience and ‘affirmative.’”

What This Means For Follow-On Manufacturers

For ANDA filers, section viii remains a viable strategy. When a drug has multiple indications and only some enjoy durable patent protection, a follow-on company can again evaluate whether to seek approval for the unpatented uses without treating the mere possibility of AB substitution for the carved-out indication as an inducement problem.

The implications begin at the molecule-selection stage, not only once litigation is underway. Drugs with multiple indications may present opportunities where a clean carve-out creates a path to market even though patents on later uses remain in force. Regulatory considerations remain important. A carve-out that works as a matter of patent law may not work if FDA concludes that the omitted information is necessary for the drug’s safe and effective use.

Commercial conduct matters, too. A company pursuing a skinny-label strategy should ensure its commercial conduct is consistent with the carve-out. A safer course is to rely on the approved indication, the approved label, and ordinary regulatory descriptions of the product, rather than creating marketing messages that can be characterized as directing physicians toward the patented use. Hikma provides a stronger defense when a company stays on that side of the line.

What This Means For Brand Companies

For brand companies, the Hikma decision invites a harder look at follow-on patent strategy. A patent on a new indication can still protect an important therapeutic discovery. But the existence of an indication patent does not necessarily mean that the patent will block generic entry for other uses of the same molecule.

That makes the practical value of the patent increasingly important. A weak follow-on indication patent obtained principally to extend Orange Book coverage may offer less protection if competitors can carve the indication out and enter for an unpatented use. And if the patent is later challenged, the strategy can create litigation risk without delivering a meaningful barrier to competition.

One consideration is whether follow-on innovations are intertwined with information FDA is likely to require across the label. Improvements involving safety, patient selection, dosing, or treatment protocols may present a different carve-out problem than a discrete new indication. Rather, the practical viability of a carve-out will depend on both the scope of the patent and what FDA requires to remain in the label. That makes it important to consider patent prosecution, regulatory strategy, and lifecycle planning together rather than as separate exercises.

Diverging Approaches In Key European Markets: The U.K., Germany, And The UPC

While the Hikma decision confirms the high threshold that brand companies must meet when pursuing induced-infringement claims in the U.S., approaches to skinny-label infringement across the large European market remains fragmented.  This creates uncertainty for both brand companies as well as their generic competitors. 

This uncertainty is particularly apparent in the U.K.  Although the U.K. Supreme Court considered skinny label infringement in Warner-Lambert Company LLC v Generics (U.K.) Ltd, the patent was held invalid and the judges’ observations on infringement were therefore obiter and non-binding. 

The majority essentially favored an objective “outward presentation” approach, which focused on whether the finished pharmaceutical product was prepared, presented and marketed for the patented use, although there was disagreement on the relevance of the subjective conditions including the manufacturer’s intention.  The alternative proposal, a “subjective-intention” test, would require the court to look behind the label and consider whether the manufacturer intended the product to be used for the patented indication.

By affording considerable weight to the proper implementation of a skinny label, the outward presentation test is favorable to generics.  That said, the subjective-intention approach aligns most closely with real world prescribing and dispensing practices, where physicians commonly prescribe by international non-proprietary name and prescriptions do not identify the relevant indication for the medicine. This would also enable the court to assess allegations that the manufacturer deliberately sought to exploit the patented use by evaluating commercial conduct.  However, unless and until the issue comes before the courts again, the U.K. position remains unsettled.

In a number of mainland Europe countries, the approach to skinny label infringement has been more settled.  In Germany, courts have historically followed a clear framework for assessing skinny-label infringement, where a generic product would only infringe if specifically prepared and marketed for the patented indication.  However, recent decisions suggest a growing willingness to consider market realities and the foreseeable consequences of generic market entry, creating some tension within the case law and the national courts.

The Munich Regional Court recently proposed less strict requirements than the Düsseldorf courts for enforcing second medical use patents in skinny label scenarios. In Fulvestrant (2019), the Düsseldorf Court of Appeals stipulated three requirements for finding infringement: (i) the generic product is objectively suitable to be used for the patented indication; (ii) the generic supplier makes use of the circumstances which lead to the product being used for this patented indication to a sufficiently relevant extent (not just on single occasions) and (iii) the supplier must be aware of these circumstances, or they must at least be obvious. The court placed considerable weight on the contents of the Summary of Product Characteristics (SmPC).  A clear and unambiguous carve-out was seen as reducing the likelihood of infringement because doctors will only prescribe the product in an off-label way if the SmPC somehow directs them to do so.

In contrast, in Nilotinib (2024), the Munich Regional Court attached greater significance to the practical consequences of the German reimbursement system, shifting the inquiry away from the label and towards market practices. Pharmacies must automatically substitute the prescribed drug with a cheaper generic version, which may therefore render patented use sufficiently foreseeable. The SmPC would not hinder doctors from their prescription practice because the generic version is an identical copy and there is no medical explanation for deviating from this practice.

There are some doubts that the Munich Court of Appeal would have confirmed the lower court’s ruling, but the case was settled prior to a decision.  Nevertheless, it would appear that a skinny-label may not provide the safe harbor for generics that it used to in Germany, and active monitoring of prescribing practices and cross-label use will be prudent. 

The developing case law of the Unified Patent Court may ultimately introduce greater harmonization for both brand companies and generic manufacturers who operate across much of Europe.  In Sanofi & Regeneron v Amgen, the Düsseldorf Local Division drew on German national case law but ultimately proposed its own two-limb objective-subjective test. 

It held that, firstly, the alleged infringer must offer or place the medicinal product on the market in a manner that leads, or may lead, to the claimed therapeutic use and, secondly, must know, or reasonably be expected to know, that this will occur. This holistic approach requires consideration of all relevant circumstances, which may include the extent and significance of the allegedly infringing use, with the label forming only one part of the analysis.

However, although significant, Sanofi is only one first-instance decision of a single local division, and the approach may be refined as further cases, including appeals, come before the UPC.

The overall picture is one of divergence between the US and key European markets. Hikma, and potentially the U.K.’s outward-presentation approach if adopted in a future case, provide comparatively strong protection for a generic manufacturer that has properly implemented a skinny label. In contrast, Germany, the UPC and some other European jurisdictions may require more active management of market practices and foreseeable patented-indication use. 

The Strategic Question After Hikma

Although the legal mechanisms differ across jurisdictions, the commercial problem is the same: how to reward meaningful investment in new uses of existing medicines without unnecessarily hindering competition in uses that are no longer patent protected.

Follow-on companies should be looking for carve-out opportunities early and aligning their patent, regulatory, and commercial strategies before launch. Brand companies, by contrast, should ask not simply whether another indication can be patented, but what that patent will actually protect once competitors can seek approval for other uses. And for both sides, marketing and litigation strategy should follow the same principle the Supreme Court emphasized in Hikma: focus on what the manufacturer actually encourages, not merely what downstream prescribers may choose to do.

Ultimately, Hikma does not eliminate the tension between follow-on innovation and generic competition. It does, however, make the U.S. rules more predictable. For generic manufacturers, section viii remains an important route to market. For brand companies, the decision is a reason to evaluate whether a new indication patent will provide meaningful commercial protection or simply another target for a carve-out and validity challenge.

The predictability provided by Hikma must, nevertheless, be viewed in a global context. The differences in approaches to skinny-label infringement across key markets are important considerations in international patenting, launch and litigation strategies, requiring brand and generic companies to walk a tightrope when developing practical launch and governance frameworks. Generics preparing for launch should assess not only the label, but also prescribing and dispensing practices, market conditions, reimbursement arrangements and any other practical measures available to discourage use for the patented indication. Brand companies, conversely, should seek evidence of positive encouragement of substantial patented-indication use, and conduct that makes such use attributable to the generic supplier.

Editor’s note: Jake M. Holdreith, Managing Partner, and Christopher A. Pinahs, Partner, Robins Kaplan LLP, as well as Chris Sharp, Partner at Pinsent Masons based in London, contributed to the writing of this article.

About The Authors:

Carla J. Baumel is a trial lawyer at Robins Kaplan who focuses on intellectual property litigation, antitrust, government investigations, and complex commercial disputes. A registered patent attorney with a background in biology, she has experience in Hatch-Waxman litigation, patent enforcement, and disputes involving the pharmaceutical and life sciences industries. She previously served as a federal prosecutor and an antitrust attorney with the Colorado Attorney General’s Office.

Ellen K. Levish is an associate in Robins Kaplan’s Intellectual Property and Technology Group, where she represents clients in complex patent and other intellectual property disputes. Her practice includes Hatch-Waxman (ANDA) litigation involving both branded and generic pharmaceutical companies. With a background in neuroscience and substantial courtroom experience, Ellen brings a scientific and trial-focused perspective to intellectual property litigation.

Kai Rüting is a partner at Pinsent Masons and a German-qualified patent litigator with extensive experience in high-value, cross-border patent disputes. He has led multi-jurisdictional litigation for pharmaceutical, biotechnology and medical technology companies, advising on enforcement, defence and dispute strategy across Europe. Kai is also highly experienced in UPC litigation and in developing pan-European patent enforcement strategies for international clients.

Sarah Taylor is a Managing Senior Practice Development Lawyer at Pinsent Masons and an English qualified patent litigator specialising in multi-jurisdictional disputes. With a particular focus on life sciences, she advises on patent law, litigation strategy and UPC developments, supporting clients and legal teams on complex cross-border issues across Europe. Sarah is a recognised commentator on patent matters, regularly contributing to industry publications and serving on the Editorial Board of The Patent Lawyer and as a UPC Editor of the EPLAW blog.