The Danish Supreme Court Establishes a Strong Validity Presumption for Patents in Preliminary Injunction Cases

On 8 January 2026, the Danish Supreme Court rendered a decision in three joined cases regarding three granted preliminary injunction orders and established a strong presumption of validity of patents.

The patentee, Bayer, had initiated preliminary injunction proceedings against, among others, three companies (Sandoz, Teva and Glenmark) marketing generic versions of Bayer’s medicinal product Xarelto^®. In the appealed decision, the Eastern High Court had granted preliminary injunctions against all three companies for the infringement of the Danish patent no. DK/EP 1 845 961 regarding once-daily administration of rivaroxaban for the treatment of thromboembolic disorders.

Since 2023, the Eastern High Court has used the following test for the alleged infringer’s objection to the validity of a patent (here quoted from the appealed decision):

“The disputed patent has been granted by the EPO after examination by the Examining Division and has been validated in this country by the Danish Patent and Trademark Office. The patent has furthermore, in the subsequent opposition procedure, been found valid and maintained as granted by the decision of the Technical Board of Appeal of 27 October 2021 in case T 1732/18.[1]

Thereafter, there exists a presumption that the patent is valid, cf. also the judgment of the Court of Justice of the European Union in case C-44/21, Phoenix Contact, paragraph 41. It therefore rests with Sandoz et al. as those who raise objections against the validity of the patent to demonstrate that the basis on which the EPO has decided to grant the patent is so clearly deficient or erroneous, or that the assessment which the Examining Division and the Technical Board of Appeal have carried out of the conditions of validity is so clearly erroneous, that the said presumption of the patent’s validity cannot be maintained, and that the patent as a consequence thereof cannot form the basis for interim prohibitions and injunctions.”

As can be seen from the quote, the Eastern High Court’s refers to the Enforcement Directive and the interpretation hereof laid out in C-44/21 in support of a presumption of validity.

Though the Supreme Court affirmed the appealed decision, it did, however, revise the test for validity in preliminary injunction cases, without referencing the Enforcement Directive, and thus indicating that the strong presumption of validity of patents in Danish preliminary injunction cases is based on the easement of the burden of proof in the Danish Administration of Justice Act and Danish case law:

“As mentioned, Bayer’s patent has been granted by the EPO and maintained by the EPO’s Technical Board of Appeal (TBA) by decision of 27 October 2021. Thereafter, there exists a strong presumption that the patent is valid. On this basis, Bayer has, as the clear starting point, substantiated the probability of its right pursuant to section 413(1)(i) of the Administration of Justice Act solely by reference to the granted patent.

[…]

The Supreme Court finds that, on the basis of the submitted information referred to, no gross or manifest deficiencies in the TBA’s case handling or application of the law have been demonstrated. Nor has it been demonstrated that the decision appears manifestly incorrect, also not as regards the new prior art that was first submitted during the injunction proceedings. The information has thus not weakened the presumption of the patent’s validity to such a degree that Bayer has not substantiated the probability of the right sought to be protected.”

The Supreme Court’s decision thus reiterates the strong presumption of validity and confirms the long-standing case law in Denmark regarding objections to validity in Denmark in preliminary injunction cases.

Most notably, the Supreme Court decided not to follow the defendants’ arguments that UPC case law and the “more likely than not threshold” adopted by the UPC Court of Appeal in Nanostring Technologies v. 10x Genomics (CoA_335/2023) showing that Danish law will not necessarily follow UPC case law in the future. Whether this only applies to procedural law or if it also applies to the UPC’s interpretation of the European Patent Convention is yet to be seen. So far, Danish courts have followed EPO practice, but the courts have not had to decide on whether to follow EPO practice or UPC case law.

Mikkel Vittrup represented Bayer in the preliminary injunction proceedings.

The Supreme Court’s decision can be found here (in Danish).

[1] The Eastern High Court has also applied this test for validity where the patent has not been upheld by Opposition Division or a Technical Board of Appeal, see e.g. the Eastern High Court’s decision in the joined cases BS-5667/2023-OLR, BS-7310/2023-OLR and BS-27713/2023-OLR