H. Lundbeck A/S v Generics (UK) Limited & Others, 10 April 2008 [2008] EWCA Civ 311

Citalopram is an antidepressant drug. The patent for citalopram was owned by H Lundbeck A/S (“Lundbeck”) and expired several years ago. It is a racemate comprising equal numbers of (+) and (-) enantiomers. Lundbeck subsequently found that the (+) enantiomer, escitalopram, was the active form and applied for a patent for it. Generics (UK) and others sought to revoke the new patent.  

At first instance, Kitchin J found that the patent was novel and not obvious. However, he held that it was invalid for insufficiency as the protection was too broad. In particular, he relied on the fact that it was already known that the two enantiomers existed and that one or other, or both, of the enantiomers had a medicinal effect. What Lundbeck had discovered was one way of making the (+) enantiomer, but it claimed every way of doing so. Holding that the claim extended beyond the technical contribution of the invention, Kitchin J considered that he was following the House of Lords decision in Biogen v Medeva.  

On appeal, the Court of Appeal overturned the first instance decision on insufficiency but agreed with Kitchin J that the patent was not anticipated or obvious. The leading judgment was given by Lord Hoffmann (coming down from the House of Lords to hear the case) who had also given the leading opinion in Biogen v Medeva. As regards insufficiency, the Court of Appeal distinguished Biogen on the basis that the claim in the present case was an ordinary product claim, and not a process claim or a “product by process” claim. The Court held that in the case of an ordinary product claim, the technical contribution is the product itself, not the process by which it is made, even if the process is the only inventive step. Therefore, disclosing only one way of making a product in those circumstances is sufficient.

In Biogen, the claim had been for a recombinant DNA molecule coding HBV (to simplify the claim) ie. a product made by a number of possible recombinant processes. In that case, only one recombinant means had been disclosed, yet all such processes were claimed and so the patent was held to be invalid for insufficiency. Lord Hoffmann in the present case stated that the claim in Biogen was a “product by process” claim, consisting of a class of products. In that case, it had been necessary to enable each product in the class (ie. teaching each way of making it), or else teach a principle of general application. That did not, however, apply to an ordinary product claim.  

The decision was somewhat surprising as it had previously been thought by many that Biogen held that a product claim had to be commensurate with the technical contribution of the patent, no matter what the form of claim. This carves out an effective exception for “ordinary” product claims. The decision is being appealed to the House of Lords.