Skinny Labels and Second Medical Use Patents: Where is the Line Moving? 22 May 2026 “Skinny labelling” sits at the intersection of two competing policy objectives: enabling timely generic entry for unpatented indications, while preserving meaningful exclusivity for second medical use innovation. While the regulatory logic is relatively clear, commercial realities often mean that a carve-out on paper does not translate neatly into segmented use in the market. Over the past 18 months, courts and regulators across major jurisdictions have repeatedly returned to the same core question: when does a generic product approved and labelled only for non-patented indications, nonetheless become responsible for patented use? While the answers continue to differ across jurisdictions, some courts have begun to adopt a more fact-driven analysis, looking beyond the label itself to consider how the product is positioned and used in practice. Skinny labels and second medical use patents Second medical use patents protect new therapeutic indications, patient subgroups, dosing regimens, or treatment protocols for known active ingredients. A skinny label is a regulatory and commercial strategy under which a generic applicant seeks approval only for non-patented indications, expressly omitting the patented use from its label. The legal risk is that, notwithstanding the carve-out, the generic’s conduct in the market may still be alleged to encourage, facilitate, or inevitably result in use that falls within the scope of the second medical use patent. United States: carve-outs exist, but intent is scrutinized In the United States, skinny labelling is grounded in the Hatch-Waxman framework. Where a reference product includes both patented and unpatented indications, a generic applicant may pursue approval from the FDA using a Section viii carve-out label. However, such a carve-out does not provide immunity from infringement claims. US courts have consistently allowed innovators to pursue induced infringement theories where a generic’s conduct is alleged to encourage use falling within the scope of a second medical use patent. The Federal Circuit’s decision in the Coreg (carvedilol) case remains the most frequently cited example. Although the patented indication was omitted from the label, liability ultimately turned on a detailed factual record concerning how the product was positioned and understood in the market. More recent decisions have reinforced that skinny labels remain permissible, but they are not determinative. In Amarin v. Hikma, the Federal Circuit revived inducement allegations notwithstanding an FDA-approved skinny label, relying on allegations that extended well beyond the label itself. The growing concern is that routine commercial activities, such as payer communications, public statements, or sales practices, may be treated as evidence of intent to induce patented use. This concern was made explicit in late 2025, when the US government reportedly recommended review by the Supreme Court, warning that an expansive view of inducement could undermine the balance Congress intended under Hatch-Waxman. In practical terms, the US analysis has shifted away from labels alone. The key question now is whether the generic’s overall conduct, viewed holistically, supports an inference of intent. Europe: second medical use enforcement in the UPC era In Europe, second medical use inventions are typically protected through purpose-limited product claims. While this approach avoids direct method-of-treatment claims, it creates enforcement challenges where a generic product is approved only for non-patented uses. These challenges were highlighted by the pregabalin litigation, which remains the policy touchstone for skinny-label disputes in the UK and across Europe. Those cases demonstrated how difficult it can be to link a generic supplier’s conduct to a patented indication in healthcare systems characterized by indication-blind prescribing and routine substitutions. The enforcement landscape is now shifting with the advent of the Unified Patent Court. In May 2025, the Düsseldorf Local Division issued what has been widely described as its first merits decision addressing second medical use validity and infringement. While UPC jurisprudence is still developing, its impact is immediate: a single UPC decision can shape enforcement strategy across multiple European jurisdictions at once. Labels remain relevant in Europe, but they are rarely determinative. Evidence relating to procurement, reimbursement, promotional intent, and foreseeable patterns of use is increasingly central to the infringement analysis. China: Swiss-type protection with practical enforcement hurdles China relies on Swiss-type claims to protect second medical use inventions, given the exclusion of methods of medical treatment from patentability. Enforcement, however, presents well-recognized challenges. Courts typically require evidence that the accused product is manufactured or sold for the patented indication, which can be difficult to establish where the label omits that use and prescribing decisions occur downstream. China’s evolving pharmaceutical patent linkage system adds a further layer of complexity. While linkage procedures may bring disputes to the surface at an earlier stage, they do not remove the evidentiary burden associated with proving infringement of Swiss-type claims. As a result, both innovators and generics are paying closer attention to alignment between patent claim scope, regulatory submissions, product labelling, and launch strategy. Singapore: skinny labelling in the absence of indirect infringement In Singapore, the interaction between Swiss-type claims and skinny-labelled pharmaceutical products remains largely untested. What distinguishes the Singapore position is that the Singapore Patents Act does not contain provisions addressing indirect infringement. This statutory feature raises a fundamental question as to whether, and how, concepts such as intention, encouragement, or downstream use could be accommodated within Singapore’s infringement framework at all. In the absence of reported Singapore decisions directly addressing skinny labelling in the context of Swiss-type claims, it remains unclear how the courts would approach alleged infringement where the relevant use occurs beyond the manufacturer’s immediate acts. Conclusion Across jurisdictions, the legal treatment of skinny labelling and second medical use patents remains fragmented, and effective protection continues to be highly jurisdiction specific. As a result, enforcement strategies must be tailored to the legal framework and judicial approach of each forum. This also has implications at the prosecution stage. Second medical use patents should be drafted with enforcement in mind, taking into account how different jurisdictions interpret “for” or “intended for” language, how narrowly therapeutic indications need to be framed to withstand validity challenges, and what types of evidence are likely to be available in the market if enforcement becomes necessary.