Dutch Supreme Court 7 June 2013, ECLI:NL:HR:2013:BZ4115 (Lundbeck/generics)

The Dutch Supreme Court has decided that Lundbeck's product claim for the substance escitalopram is valid in view of the inventive method of manufacture of this substance disclosed in Lundbeck's patent.

Since 1989 and 2002 respectively, Lundbeck has been marketing the antidepressants Cipramil (with the active ingredient citalopram) and Cipralex (with the active ingredient escitalopram). Citalopram is a so-called racemic mixture or racemate of two different enantiomers, a (+) and a (-) enantiomer (also referred to as S- and R-enantiomers). Enantiomers are stereo- isomers, i.e. substances with an identical chemical formula and atom sequence, but with a different spatial configuration. Escitalopram is the (+) or S-enantiomer of citalopram.

Lundbeck is the owner of the European patent EP 0  346 066, which comprises product claims protecting the product escitalopram as well as method claims protecting a method of manufacturing escitalopram. In 2008, the generic companies Alfred Tiefenbacher, Centrafarm and Ratiopharm initiated patent revocation proceedings with respect to Lundbeck's patent before the District Court of The Hague. Lundbeck counterclaimed for an injunction.

The District Court of The Hague considered that both the product claims and the method claims for escitalopram lacked an inventive step and revoked Lundbeck's patent in its entirety. This decision was appealed by Lundbeck. In appeal, the Court of Appeal considered that the claimed method of manufacture exhibited an inventive step, but that the product claims lacked an inventive step as the composition and possible features of escitalopram in themselves were known and it would have been obvious on the priority date that one of the enantiomers of citalopram would have an increased activity vis-à-vis the racemate. Lundbeck’s claim that there was no known method to obtain the enantiomers of citalopram on the priority date was held to be irrelevant. The Court of Appeal thus upheld the method claims, but confirmed the invalidation of Lundbeck’s product claims on the basis of lack of inventive step.

Lundbeck successfully appealed the Court of Appeal's decision before the Supreme Court. The Supreme  Court considered that a substance of which the composition and possible features are in themselves known and which substance for that reason follows  from the state of the art in an obvious manner, can nevertheless be non-obvious and patentable if on the priority date the state of the art did not include a method for obtaining this substance and with the claimed method this substance can be obtained for the first time in an inventive manner. After all, in that case also the substance, although in itself known in terms of composition and possible features, does not follow from the state of the art in an obvious manner.

According to the Supreme Court, its decision is in line with established case law of the Technical Boards of Appeal of the European Patent Office (decisions T 595/90, T 1412/04, T 441/02, T 803/01 and T 268/98)

and decisions of the highest courts in Germany and the United Kingdom which also decided – with regard to the same patent – in this sense (GBH 10 September 2009, Xa ZR 130/07 and – although inventive step as such was no longer at issue in this decision – House of Lords, UK, 25 February 2009, [2009] UKHL 12).

The generics' cross-appeal before the Supreme Court was rejected. The Supreme Court considered that the burden of proof of invalidity rests on the party claiming that the patent is invalid (i.e. the generics) and that the Court of Appeal made no error in deciding that the claimed method of manufacture of escitalopram exhibited an inventive step. The Supreme Court furthermore considered that, when answering the question whether an invention meets the requirement of inventive step, the Dutch court is not obliged to apply the ‘problem-and-solution-approach’ (even though the ‘problem-and-solution-approach’ is often applied by the Dutch courts in practice).

The Supreme Court's decision is favorable to innovative pharmaceutical companies, as product claims for a substance can be obtained (and upheld) on the basis of a disclosure of an inventive method for obtaining this substance, if on the priority date the state of the art does not include a method for obtaining this substance and with the claimed method this substance can be obtained for the first time in an inventive manner. The decision furthermore shows that Dutch courts, including the Supreme Court, take account of decisions of the EPO and foreign courts, such as the UK and German courts, when rendering decisions in patent cases.