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MSD’s Recent Injunctive Relief – A New Dawn for Patent Litigators in Ireland

A recent court decision granted Merck Sharp and Dohme Ireland (Human Health) Limited (MSD) injunctive relief regarding its supplementary protection certificate (SPC) for the combination sitagliptin and metformin. The combination is sold under the brand name Janumet. Janumet is an inventive treatment for diseases, including type 2 diabetes. The decision, which was delivered on 22 January 2023, centres around the EU SPC Regulation and the conditions required to obtain a certificate in Section 3 of the Regulation. We examine why Mr. Justice Sanfey sided with the patentee in a decision which sees a change in position in favour of patentees who seek injunctive relief in the Irish Commercial Court.


The respondent, Mylan, planned to launch a generic version of Janumet at a considerable discount, before the SPC expires on 7 April 2023. In addition to the fact that Mylan’s entry to the market would destroy MSD’s monopoly, MSD were also concerned that this would trigger six other companies that have obtained marketing authorisations to enter the market.

The provisions of Section 3 of the SPC Regulation include the requirement that the product “is protected by a basic patent in force”. In its defence and counterclaim, Mylan argued that the basic patent was invalid, seeking an order revoking the SPC. Mylan argued that the mere disclosure of the combination of sitagliptin and metformin in the original patent does not satisfy the requirement that the product “is protected by a basic patent in force”.

The test to determine if a product ‘is protected by a basic patent in force’

MSD claimed that its application was equivalent to the injunctive application made in Clonmel Healthcare[1], and argued the decision of the Supreme Court should be followed. In that dispute, MSD sought an injunction preventing Clonmel Healthcare from launching an alternative to MSD’s product, Inegy, at a discount of approximately 92%. The Supreme Court noted that it was not always possible to follow the American Cyanamid/Campus Oil test where damages are not an adequate remedy. In these cases, additional factors should be considered, specifically, whether there have been proceedings in other jurisdictions, whether the defendant had “cleared the way”, and the presumption of validity.

Mr Justice Sanfey analysed the relevant factors considered in the Clonmel Healthcare, which was ultimately appealed to the Supreme Court[2]. Clonmel Healthcare had challenged the validity of the SPC for Inegy, a combination of ezetimibe and simvastatin. This case also concerns the conditions required to obtain a certificate under Section 3 of the SPC Regulation. Both the Irish High Court and Court of Appeal agreed that, for the patent to protect the combination of ezetimibe and simvastatin, the combination must be an invention covered by the patent. Mylan relied heavily on the views of these courts, and the application of the “invention test”.

The Supreme Court have deemed that Article 3 of the SPC Regulation could not be considered acte clair or clear. As a result, the Supreme Court have referred certain questions to the Court of Justice of European Union (CJEU) on what test should be applied when determining whether a product “is protected by a basic patent in force”. The ambiguity surrounding Article 3 follows the interpretation of a previous judgment by the CJEU in Teva v Gilead and the issue of whether an “identificatory” test or an “inventive advance” test should be applied in determining whether the product “is protected by a basic patent in force”. MSD pointed to the finding by the Supreme Court that the law is unclear and requires clarification from the CJEU and to the fact that this is binding on the court.

The interlocutory injunction principles considered

Historically, in Irish patent injunction cases, the key element in considering the balance of convenience and justice is the adequacy of damages. The judge in Clonmel concluded that the balance of potential irreparable harm in the present case favoured neither party decisively. The judge considered that the principles set down in the Clonmel Healthcare interlocutory injunction hearing should be applied in these circumstances where the balance of convenience test applied is so finely balanced that it favours neither party. The court continued by considering rival arguments and proceedings in other jurisdictions, to determine whether Mylan had “cleared the way” and the presumption of validity.

In considering a recent injunction hearing involving Biogen[3], Mr Justice Sanfey noted that Mylan did not argue that there is no presumption of validity regarding the original patent. The judge confirmed that in the interlocutory application in Clonmel Healthcare, the Supreme Court said that “successive determinations in Clonmel’s favour of a similar challenge in other jurisdictions…” may weigh against the grant of an injunction. However, the judge confirmed that Mylan had not provided sufficient evidence of such determinations. Finally, Mr Justice Sanfey concluded that Mylan had not been proactive in challenging the SPC in this jurisdiction, and the fact that Mylan had not “cleared the way” was an additional factor in persuading the court to grant the injunction in favour of MSD.


The question posed to the CJEU through the Clonmel Healthcare case, regarding the test to determine if a product ‘is protected by a basic patent in force’, has yet to be answered. However, we have gained insight into additional principles that are to be considered before allowing an injunction, thanks to that same case.

The Supreme Court in Clonmel Healthcare recognised that it is not always possible to follow the traditional test in American Cyanamid/Campus Oil when damages would not be an adequate remedy. The court identified additional factors that are to be considered before allowing an injunction. These factors, including the consideration of proceedings determined in other EU countries, has certainly changed the injunction playing field for patentees and generics. This can be seen by Mr Justice Sanfey’s considerations and ultimate decision in the most recent injunction application, discussed above. Generics may now need to consider these additional factors when a launch in Ireland runs the risk of injunctive proceedings being brought.

For more information and expert guidance on successfully protecting your company’s intellectual property rights, contact a member of our Intellectual Property team.

The content of this article is provided for information purposes only and does not constitute legal or other advice.

[1] Merck Sharp & Dohme Limited v. Clonmel Healthcare Limited [2019] IESC 65

[2] Merck Sharp & Dohme Limited v. Clonmel Healthcare Limited [2022] IESC 11

[3] Biogen MA Inc. & Biogen International GMBH v Laboratorios Lesvi SL & Neuraxpharm Ireland Ltd. [2022] IEHC 592,

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