Eli Lilly and Company, ICOS Corporation, and Eli Lilly Danmark A/S (“Eli Lilly”) v. Generics (UK) Limited and Mylan AB (“Mylan”), the Danish Maritime and Commercial High Court, Case number BS-33415/2018-SHR, 1 February 2019

The case concerns infringement of Eli Lilly’s patent DK/EP 1 173 181 T6 (“DK/EP ‘181”) which relates to the use of the active substance tadalafil in a dosing regime and applications thereof, including for the treatment of sexual dysfunction, wherein tadalafil is administered up to a maximum of 5 mg tadalafil per day.

Eli Lilly markets tadalafil under the trademark CIALIS® in four strengths; 2.5 mg, 5 mg, 10 mg and 20 mg. The tablets with 10 mg and 20 mg are for use “on demand” while the tablets with 2.5 mg and 5 mg can be used as a “once a day” dosage regimen.

In September 2018, Mylan began marketing in Denmark of its generic version of Cialis®, Tadalafil “Mylan”, in the strength 5 mg, and Eli Lilly immediately filed a request for a preliminary injunction. On 1 February 2019, the Danish Maritime and Commercial High Court handed down its decision granting a preliminary injunction against Tadalafil “Mylan” with the strength 5 mg.

During the proceedings, Mylan had claimed that DK/EP ‘181 was invalid due to lack of inventive step. Mylan argued that the invention was obvious in light of the patent application WO-A-97/03675 (Daugan II) and the skilled person’s knowledge of the known PDE-5 inhibitor sildenafil (Viagra®).

Furthermore, Mylan claimed that there was no presumption that the granted patent DK/EP ‘181 was valid, as the patent claims had been limited through EPO’s limitation procedure so that claim 1 of DK/EP ‘181 is now limited to comprise a unit dosage of 1 to 5 mg tadalafil to be administered up to a maximum dose of 5 mg tadalafil per day, instead of a unit dosage of 1 to 20 mg tadalafil to be administered up to a maximum dose of 20 mg tadalafil per day as stated in claim 1 of the patent as initially granted.

Mylan argued that EPO’s limitation procedure does not entail a renewed examination of whether the limited claims meet the patentability requirements, including regarding novelty and inventive step.

Eli Lilly maintained that the patent is valid and that there is still a presumption of validity, despite the limitation of the patent claims. The Court found that the fact that a patent had been limited in the limitation procedure does not entail that the presumption of validity ceases.

In this connection, the Court stated that the EPO had granted DK/EP ‘181 after examining whether it meets the patentability requirements. The fact that the claims have been limited and the EPO during the limitation procedure solely examines whether the limited claims
1) constitute a limitation compared to the claims of the initially granted patent,
2) are clear and concise, cf. EPC art. 84,
3) do not extend beyond the application as filed, cf. EPC art 123(2), and
4) do not extend the protection conferred, cf. EPC art 123(3), does not alter the fact that there is still a presumption that the limited patent is valid, including that it meets the requirements regarding novelty and inventive step.

Accordingly, the Court found in favor of Eli Lilly that there was a presumption that DK/EP ‘181 is valid.

Based on a thorough analysis of the question regarding inventive step, the Court found in favor of Eli Lilly, i.e. that Mylan had not rendered it probable that DK/EP ‘181 was invalid. It is noted in the decision that both Daugan II and information regarding the properties of sildenafil is mentioned in DK/EP ‘181 and that Daugan II and a publication regarding Viagra was examined by the EPO during the examination of the patent application.

It was thus concluded that Eli Lilly had rendered it probable that DK/EP ‘181 is valid.

During the proceedings Mylan did not contest that if DK/EP ‘181 was valid, it was also infringed by the 5 mg tablets. On this basis, the court granted a preliminary injunction against sale and marketing etc. of Tadalafil “Mylan” with the strength of 5 mg.

The decision has not been appealed by Mylan.

You can read the decision (in Danish) here.

Reported by: Mikkel Vittrup, Peter-Ulrik Plesner, Mette-Marie Henrichsen and Nina Charlotte Vestergaard, Plesner Advokatpartnerselskab, and Ejvind Christiansen and Pernille Thorsboe, Zacco, who advised Eli Lilly during the PI proceedings in Denmark