Preliminary injunction granted against generic Nexium product

On 15 January 2010, in a case between AstraZeneca and Sandoz A/S (Sandoz), the Enforcement Court in Copenhagen granted an interlocutory injunction against Sandoz enjoining them from marketing a drug containing generic esomeprazole magnesium. The Enforcement Court found that Sandoz did not make it probable that the patent-in-suit was invalid. AstraZeneca was represented by Sture Rygaard, Attorney-at-Law.


On 2 April 2009, the Danish Medicines Agency granted Sandoz approval to market a generic version of AstraZeneca's Nexium (esomeprazole magnesium). Despite warning letters sent to Sandoz in April and May, Sandoz decided to launch the product on the Danish market in June 2009. AstraZeneca analysed the products and found that they infringed their substance patent.

As Sandoz refused to withdraw the product, AstraZeneca filed a request for interlocutory injunction in June 2009 in order to prevent Sandoz from marketing their generic Esomeprazol "Sandoz" product in Denmark. AstraZeneca claimed that the products marketed by Sandoz infringed AstraZeneca's patent covering esomeprazole magnesium with an optical purity of at least 99.8% enan-tiomeric excess.

During the proceedings, Sandoz claimed that the patent-in-suit was invalid due to alleged errors made by the EPO. Further, Sandoz argued that a prior German patent application in combination with a prior AstraZeneca patent allegedly enabled the invention. The main question during the proceedings was whether the German patent application showed a specialist how to obtain esomepra­zole with a very high optical purity as comprised by the patent-in-suit. In support of this argument Sandoz sub­mitted experimental data from their affiliate company LEK Pharmaceuticals (LEK).

LEK's experiments had in part been monitored by a Dan­ish professor from the Pharmaceutical University in Co­penhagen. However, AstraZeneca was able to show that some of the main data in LEK's test report were seriously in error and, in fact, supported that the invention was not enabled by prior art.

Injunction granted by the District Court of Copenhagen

The Enforcement Court (the District Court of Copenha­gen) did not find that Sandoz had substantiated its alle­gation that the German patent application enabled the production of esomeprazole with a very high optical purity to such an extent that it could set aside the exist­ing presumption that AstraZeneca's patent was valid.

The Enforcement Court found that it had been rendered probable that Sandoz' sale of Esomeprazol "Sandoz" as covered by Sandoz' marketing authorisation, and of medicinal products with a similar chemical composition, was contrary to AstraZeneca's right according to the patent-in-suit.

Accordingly, and since the other conditions for granting an injunction were found to be fulfilled, the court issued a preliminary injunction and also imposed the ancillary obligation on Sandoz to recall the products from the distributors and pharmacies, as AstraZeneca had claimed. Sandoz has appealed the decision, but as this does not have delaying effect under Danish law, the preliminary injunction remains in effect.

If you have any questions to the decision, you are wel­come to contact Sture Rygaard, Attorney-at-Law,