Lovells

The Court of Appeal has today allowed Lundbeck's appeal from the decision that its patent relating to the antidepressant escitalopram (Cipralex) should be partially revoked.  The judgment clarifies the law of sufficiency: the statutory requirement for a patent specification to "disclose the invention clearly enough and completely enough for it to be performed by a person skilled in the art", which aims to prevents a patent giving a monopoly over something it does not tell people how to achieve.  At first instance, Mr Justice Kitchin applied the House of Lords decision in Biogen v Medeva and concluded that two of the patent claims were insufficient.  Lord Hoffmann, who gave judgment in Biogen, came down to the Court of Appeal to hear the appeal in this case. He held that Mr Justice Kitchin had taken Biogen too far.

Escitalopram is the (+) enantiomer of citalopram, also an antidepressant, which is now off-patent and sold by generic companies. Mr Justice Kitchin held that the patent claims for the product (the (+) enantiomer of citalopram and a formulation containing it) were insufficient. His reasoning was that the product claims covered all ways of making the product whereas the patent only disclosed one.  However, Lord Hoffmann said this conclusion did not follow from the decision in Biogen. 

The patent claim in Biogen was not a simple product claim but a "product-by-process" claim, claiming a class of products all made by recombinant DNA technology.  The patent specification in Biogen described only one method of making the class of products. The important point that had been missed in the first instance Lundbeck decision, according to Lord Hoffmann's decision, was that Biogen related to a class of products. In the Lundbeck case, the product claims were to a single product and the "Biogen insufficiency" did not arise.

The patent was held valid despite the first instance findings that the (+) enantiomer was known to exist and known to be desirable. Crucially, however, it seems that the Lundbeck patent disclosed for the first time a way of producing that (+) enantiomer. As production of the (+) enantiomer was not taught by the prior art, the (+) enantiomer was novel. Further, the method of producing it was not obvious. Although Lundbeck disclosed only one way of making it, the result is that Lundbeck has a monopoly to the (+) enantiomer regardless of how it is made. Lord Hoffmann and Lord Justice Jacob both comment about the odd consequences that arise from such product claims. But as Lord Hoffmann points out "It is too late to have regrets about the breadth of the monopoly which such claims confer".

Jacob LJ agreed with Lord Hoffmann.  He said the claim is to the (+) enantiomer and the answer to the straightforward question "Does the patent enable the skilled man to make it?" is an equally straightforward "Yes" - therefore, in the words of the statute, the patent discloses "the invention in a manner sufficiently clear and complete for it to be carried out".  He thought the judge's error was caused by his reasoning that if it was known that the product existed and all that was invented was a particular way of making it, then the patent claim should be correspondingly limited.  But he said that the concept "that the patentee should not have more than he deserves" did not form part of the statutory test for sufficiency.

The decision is good news for Lundbeck, foreclosing efforts by generic companies to avoid the patent by using different techniques to make the (+) enantiomer. The decision does, however, leave open the question of how much more than 50% of the (+) enantiomer must be present for a product to fall within the claim.

H. Lundbeck A/S v Generics (UK) Limited and Others [2008] EWCA Civ 311