Background
Patent protection for the use of a known drug in a new method of medical treatment can be achieved at the European Patent Office via a second medical use claim in the format [known drug] for use in [novel and inventive medical use]. Second medical use claims can be used to protect the use of known drugs in a wide variety of new therapeutic approaches, including new indications, new dosages and new patient groups.
Enforcement of such second medical use claims is the responsibility of national courts around Europe. It is fair to say that those national courts have not yet determined a settled and consistent approach to the legal principles which should apply. In particular, the following issues have been the subject of discussion in recent jurisprudence.
- A generic version of new drug can be launched with a Summary of Product Characteristics (SmPC) which excludes references to patented indicationssup>1 (a so-called "skinny label"). Does marketing the drug under a "skinny label" which excludes reference to a patented indication necessarily avoid infringement?
- Should a generic company infringe a second medical use claim if it is reasonably foreseeable that the generic drug will be used in the patented indication?
- Should a stricter test be applied for assessing infringement: e.g. a requirement that the generic product be sold such that it is "manifestly prepared" for the patented indication2> or such that the generic manufacturer must have a subjective intention that the generic product should be used to treat patients for the patented indication3?
The situation is complicated by the fact that many previous decisions from national courts have considered second medical use claims in the old "Swiss-style" claim format, which refer explicitly to the manufacture of a medicament. It was not always clear whether and to what extent reasoning in such cases could be applied when considering claims in the new "compound for use" claim format outlined above.
Sanofi & Regeneron v Amgen at the UPC (UPC CFI 505/2024)
The long-running dispute between Sanofi/Regeneron and Amgen concerns a pharmaceutical composition comprising an anti-PCSK9 antibody. The Düsseldorf local division of the UPC issued a decision on 13 May 2025 under EP3536712. The relevant claim was for a composition comprising the antibody for use in reducing lipoprotein(a) levels (Lp(a)) in specified patients.
The Amgen group markets evolocumab (an anti-PCSK9 antibody embraced by the definition of the API in EP3536712) under the trade name Repatha®. The SmPC for Repatha® notes the therapeutic indications as (in summarised form) lowering LDL-C and mixed hyperlipidaemia. The "pharmacodynamic effects" section of the SmPC notes, among other factors, that Repatha® lowers Lp(a).
The UPC was tasked with determining whether the Repatha® product infringed EP3536712. In doing so, it was necessary for the court to indicate the legal principles which should apply when assessing infringement of a second medical use claim. The court held that a "foreseeability" test should be applied under these circumstances:
"It is the opinion of the Court that, for a finding of infringement of a second medical use claim, the alleged infringer must offer or place the medical product on the market in such way that it leads or may lead to the claimed therapeutic use of which the alleged infringer knows or reasonably should have known that it does. In other words, as an objective element, there must be either a prescription in order to lower Lp(a) levels, or there must be at least circumstances showing that such a use may be expected to occur. In addition, as a subjective element the infringer must know this or reasonably should have known." (paragraph 182 of the Decision, emphasis added)
The court went on to indicate that a "skinny label" may not be sufficient to escape infringement4. It noted that when considering whether or not the alleged infringer knows (or should have known) that its product would be used in the patented indication, an analysis of "all of the relevant facts and circumstances" is necessary. It noted that relevant facts may include:
- the extent or significance of the allegedly infringing use;
- the relevant market including what is customary on that market;
- the market share of the claimed use compared to other uses;
- what actions the alleged infringer has taken to influence the
respective market, either:
- "positively", de facto encouraging the patented use; or
- "negatively" by taking measures to prevent the product from being used for patented use5.
Ultimately, the infringement action failed on the facts of the case. That is because the court found that the claimants had not provided sufficient evidence to establish that the infringing product was actually being prescribed for the patented indication. The court did not accept that merely including a refence to lowering Lp(a) in the section of the SmPC detailing pharmacodynamic effects was sufficient to establish that prescriptions of Repatha® were made for the specific purpose of lowering Lp(a) – rather such prescriptions were made for the purpose of achieving the therapeutic effects of lowering LDL-C and mixed hyperlipidaemia.
The court noted, though, that evidence could have been provided to show that prescriptions of Repatha® had been made (or were likely to be made) for the specific purpose of lowering Lp(a). The implication here was that if such evidence had been adduced, the court would have found infringement6.
Implications for the future
This is an important contribution to the legal jurisprudence on infringement of second medical use claims, and it is interesting to see the Düsseldorf Local Division of the UPC taking an approach which is somewhat at odds with a number of earlier decisions of the German national courts on this topic.
This is only a first instance decision, and the UPC Court of Appeal in Luxembourg may well be asked to consider these issues in the near future. However, it may be that we are now on the way to establishing a set of principles governing infringement of medical use claims which are likely to apply across Europe: given the dominance of the UPC court structure in the European patent ecosystem, it is likely that other national European courts will follow the lead given by the UPC.
Of course, many issues remain outstanding, not least that of an appropriate remedy if/when a finding of infringement arises. If damages are calculated on the basis of lost sales by an innovator company following launch of a generic product, that could potentially exceed the entire profit margin on generic sales, given price differentials following generic entry to the market. It will be interesting to see how these issues are determined in future cases.
Footnotes
1. Article 11 of EU Directive 2001/83/EC
2. A number of cases from the German national courts have adopted this approach
3. This test was considered in the UK Supreme Court in Warner Lambert v Actatvis.
4. Paragraph 184 of the Decision.
5. Paragraph 183 of the Decision
6. Paragraph 193 of the decision.
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