Infringement Of Second Medical Use Claims And Proof Of Infringement

The patentability of second medical use claims is explicitly regulated under EPC 54(5) with the amendments made to the European Patent Convention (“EPC”) in 2000, which entered into force on 13 December 2007. In Türkiye, although there is no explicit provision on this issue in the Industrial Property Code no. 6769, the discussions regarding the patentability of these claims have ended with the decision of the General Assembly of the Court of Appeal dated October 21, 2021¹. However, in terms of second medical use patents, the main debate today centers on the methods by which infringement of these patents can be determined and under which conditions infringement or the risk of infringement can be said to exist, rather than patentability. Since second medical use patents protect a new use of a known active ingredient or medicinal product, a more complex infringement assessment arises when generic products falling within the scope of the second medical use patent are placed on the market.

In principle, generic medicinal products are expected to have the same summary of product characteristics (“SmPC”) and patient information leaflet content as the products they reference in their marketing authorization applications. However, it is a common practice in the pharmaceutical industry for generic pharmaceutical companies to carve-out indications for which second medical use protection continues from the SmPCs of their products in order to avoid a clear patent infringement.

However, due to off-label use or cross-label use, which are frequently encountered in practice, even if the patented indication has been removed from the SmPC, it is possible for the generic product to be prescribed or used for the second medical use indication protected by the patent, thereby bringing patent infringement into question. For these specific infringement scenarios, courts have developed different criteria for determining infringement of second medical use patents.

The Düsseldorf Higher Regional Court’s Östrogenblocker² and Fulvestrant³ decisions constitute examples of such cases; through these decisions, the Court adopted an approach based on a broad understanding of liability in the assessment of infringement of second medical use patents.

In its Östrogenblocker decision dated 5 May 2017, the Düsseldorf Higher Regional Court held that a generic pharmaceutical company may be held liable for infringement of a second medical use patent if the following conditions are met, even where the generic product has not been specifically prepared and placed on the market for the patent-protected indication:

• The product placed on the market is suitable for the use (indication) protected by the patent.
• The generic company exploits the circumstances in a manner that results in the patented use being carried out.
• The patent protected use occurs to a sufficient extent
• The person placing the medicinal product on the market knows or should reasonably know about such use.

This decision showed that the removal by generic pharmaceutical companies of the patent-protected indication from the SmPC may not, on its own, be sufficient to prevent the product from being used for the patented indication. The Düsseldorf Higher Regional Court confirmed this approach in its Fulvestrant decision dated 9 January 2019 and reinforced the applicability of the new criteria.

Lastly, in its decision⁴ dated December 4, 2024, the Munich Regional Court held that the generic company could be liable for cross-label use, despite the fact that the generic product’s SmPC contained a warning that patients requiring the patent-protected administration regimen should use alternative products. The Court considered together the fact that the generic was covered by the statutory substitution mechanism in Germany and that physicians knew that the active ingredient in question could be used for the patent-protected administration regimen, and concluded that this meant that the generic company had exploited the circumstances of the market in such a way that resulted in the patented use being carried out.

In line with the evolving case law of the German courts, it has become clear that a mere carve-out by generic pharmaceutical companies of the patent-protected indication from their SmPC documents is not always a sufficient measure to prevent infringement of second medical use claims. This approach suggests that generic companies should not be content with a passive carve-out, but should adopt a proactive attitude to prevent the realization of the patented use, monitor cross-label uses in the market and, where necessary, take reasonable and effective measures to prevent such uses.

In its decision⁵ dated May 13, 2025, the Düsseldorf Local Division of the Unified Patent Court (“UPC”) also made an assessment for the determination of infringement of second medical use claims and accepted that the following two elements must be met together for the establishment of infringement.

• Objective element: The product has been offered or placed on the market in such a way as to lead or may lead to the intended therapeutic use.
• Subjective element: The alleged infringer knew or should reasonably have known that such use is to be expected.

The UPC further stated that whether or not these elements are satisfied should be assessed on a case-by-case basis, in light of the specific circumstances of each case. In this context, the UPC noted that the wording of the SmPC, the market share of the claimed use, prescribing practices and the steps taken to promote or prevent the claimed use may be relevant to this assessment.

When all these recent judgments are evaluated together, it is seen that courts are now adopting more comprehensive approaches in the assessment of infringement of second medical use patents, taking into account practices such as off-label use and cross-label use. Accordingly, it is clear that a mere carve-out of the patent-protected indication from the SmPC is not always considered sufficient to eliminate the risk of infringement.

It has also been accepted in Turkish court decisions that the removal by generic companies of statements referring to the patented use from the SmPC document of the generic product may not, on its own, be sufficient to eliminate the risk of patent infringement.

Indeed, in a case heard before the Turkish courts, the patentee sought a determination and prevention of the indirect use of the patent, together with a preliminary injunction, based on a patent disclosing a combination of active ingredients (X) and (Y), the scope of protection of which did not require these combination partners to be present in the same pharmaceutical form and/or together, nor did it contain any similar limitation. Although the defendant argued in the case that the SmPC document for its product containing only active ingredient (X) did not include any statements referring to the patent-protected combination use, the court did not limit its assessment solely to the SmPC document.

The court considered the patentee’s allegations that the product was in fact being used on the market together with active ingredient (Y) to be serious allegations requiring investigation. Since it was not possible for the patentee to prove such use by its own means, the court sent writs to the Social Security Institution (“SSI”) and three large-scale hospitals in Türkiye, requesting them to inform the court whether the defendant’s product had been prescribed together with active ingredient (Y) and whether it had been reimbursed on that basis. The responses provided by the SSI and the hospitals demonstrated that the defendant’s product had been prescribed together with active ingredient (Y) in a significant number of patients, and that this use had been reflected in the reimbursement system. Accordingly, even though the statements referring to the patented use had been removed from the SmPC, it was established through concrete data that the defendant’s product was in fact being used for the patent-protected combination use. In light of these findings, the court granted a preliminary injunction preventing reimbursement by the SSI of the defendant’s product in cases where it is prescribed together with active ingredient (Y).

In this context, the criteria used by courts both globally and in Türkiye for determining infringement of second medical use patents are evolving day by day, and the relevant case law is taking shape accordingly. Whether the case law on the determination of infringement of second medical use patents will become settled in the future, or whether any legislative update will be introduced in this field remains an important issue to be monitored.

Footnotes

1.https://gun.av.tr/insights/updates/a-milestone-decision-on-the-patentability-of-second-medical-use-claims

2. OLG Düsseldorf, I-2 W 6/17, May 5, 2017

3. OLG Düsseldorf, I-2 U 27/18, January 9, 2019

4. LG Munich I, 21 O 14559/24, December 4, 2024

5. UPC_CFI_505/2024, May 13, 2025

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