On May 13, 2025, the Unified Patent Court (UPC), through the Düsseldorf Local Division, issued its first ever decision concerning a second medical use claim.
The case opposed Regeneron Pharmaceuticals Inc., proprietor of European patent AP 3 536 712 B1, and its exclusive licensee Sanofi Biotechnology SAS, which markets the anti-PCSK9 antibody “Praluent”, against seven European entities of the Amgen group marketing the competing antibody “Repatha.”
Believing that the latter was being used for the same therapeutic purpose, Regeneron and Sanofi filed an infringement action (ACT_597355/2023) before the Düsseldorf Local Division on November 30, 2023, including requests for injunction, recall, destruction, disclosure of commercial information, and damages.
Amgen responded with a counterclaim for revocation of the patent (CC_24999/2024), challenging priority, novelty, inventive step, sufficiency of disclosure, and alleging extension of subject-matter beyond the content of the application as filed.
At the center of the case was Claim 1, classified as a second medical use under Article 54(5) EPC, namely the use of a PCSK9 inhibitor to reduce lipoprotein(a) [Lp(a)] in a patient who (1) has an Lp(a) level > 30mg/dL, (2) is at cardiovascular or thrombotic risk, and (3) is not on statin therapy.
The Local Division first addressed the plaintiffs’ standing under Articles 47(2) and 47(4) UPCA. Based on two license agreements (HE 38, HE 56), a cross-license and commercialization agreement for Praluent (PCLCA, BP 73), the court confirmed that Sanofi held an exclusive license, entitling it to bring legal action.
Amgen’s objection claiming lack of knowledge regarding the authenticity or scope of these agreements was rejected. According to Rule 171.2 RoP, such a challenge must be detailed and evidence-based, which Amgen failed to provide. Consequently, both Regeneron (patent holder) and Sanofi (exclusive licensee) were recognized as having standing.
The Division recalled that second medical use refers to “a substance or composition within the meaning of the Art. 54(4) EPC is used for any specific use which is not comprised in the state of the art. Such a therapeutic use can be a new indication, e.g., a disease not yet treated by the claimed substance, or an indication for a new group of patients.”
In this case, the Local Division rejected the request for revocation of the patent:

Validity of the Priority

The court found that priority was validly claimed, since all elements of Claim 1, particularly the combination “non-statin patient + Lp(a) > 30 mg/dL,” were explicitly disclosed in the priority application (Table 3B and claims 11 and 27).

Novelty (Article 54(5) EPC)

The Local Division emphasized that novelty of a second medical use lies not in the molecule itself (already known), but in its specific therapeutic use. The purpose here was not to determine whether the anti-PCSK9 antibodies were novel, but to determine whether using them specifically to reduce Lp(a) constituted a novel therapeutic use under Article 54(5) EPC.
The Local Division therefore considered that, even though anti-PCSK9 antibodies were already described for lowering LDL cholesterol, their targeted use to reduce Lp(a) levels constituted a novel use within the meaning of Article 54(5) EPC, without the need to provide a prior document showing this new use.

Inventive Step

The Local Division considered that as of 2011, the scientific community did not know whether the LDL receptor participated in Lp(a) clearance.
Clinical data were sparse and contradictory, and genetic studies provided no indication that PCSK9 inhibition would lower Lp(a). Thus, a skilled person would not have been motivated to try PCSK9 inhibitors for this purpose, especially in non-statin-treated, high-risk patients with Lp(a) > 30 mg/dL.
The invention was therefore found to be non-obvious, and inventive step was acknowledged.

Sufficiency of Disclosure

“In the case of a second medical use claim, the claimed “use”, which is based on a therapeutic effect, is part of the claim. Therefore, the use (including the therapeutic effect) has to be sufficiently (reproducibly) disclosed in the patent (as a whole).”
Applying this principle, the Local Division found the disclosure to be sufficient: Table 3B showed an average reduction of –43.8% in Lp(a) compared to placebo in patients not treated with statins after 57 days of administration of the anti-PCSK9 antibody. Such a result, directly linked to the claimed therapeutic effect, enabled the skilled person to reproduce the invention without undue difficulty, thus satisfying Article 83 EPC.

Compliance with Article 123 (2) EPC (Added Matter)

The Local Division relied on a principle established in the CoA Decision of 14 February 2025 Abbott v. Sibio, in which “the Court must thus first ascertain what the skilled person would derive directly and unambiguously using his common general knowledge and seen objectively and relative to the date of filing, from the whole of the application as filed, whereby implicitly disclosed subject-matter, i.e. matter that is a clear and unambiguous consequence of what is explicitly mentioned, shall also be considered as part of its content.”
In this case, the Local Division considered that the combination of a patient not treated with statin and presenting an Lp(a) > 30 mg/dL was already present, as is, in the original application: it appeared in Table 3B and in the claims. No passage excluded or discouraged this combination. Claim 1 of the patent therefore merely specified, without adding new information, a configuration that was explicitly (or implicitly) disclosed. The Local Division thus concluded that the condition of Article 123(2) EPC was fulfilled.
Regarding infringement, the Division held that, in the field of second medical use patents, it must be established that the infringer: (i) offers or places the product on the market in such a way as to lead or be able to lead to the claimed therapeutic use (objective criterion), (ii) knowing or having reasonable grounds to know that this will result in the respective use (subjective criterion).
In this case, the SmPC (Summary of Product Characteristics) of the disputed medicine "Repatha" mentioned the claimed therapeutic indication — the reduction of Lp(a) — only under pharmacodynamic data; the authorized indication concerned only the lowering of LDL-C, and no evidence of active promotion or prescriptions targeting Lp(a) had been provided.
Infringement was therefore dismissed, as the two elements necessary to establish infringement (objective and subjective) were lacking.
Finally, the costs were shared: Sanofi-Regeneron bore the costs of the main infringement action and Amgen those of the revocation action, each up to the limit of €1,875,000 (UPC ceiling).

More information at www.upc-casalonga.eu.