In Generics (UK) Ltd v H Lundbeck A/S [2009] UKHL 12, the House of Lords has provided some clarity in relation to sufficiency, in particular with respect to another, oft cited, House of Lords decision in Biogen v Medeva [1997] RPC 1.


The patent in question claimed the (+) enantiomer of citalopram. The racemic mixture of citalopram was known at the priority date and was a commercially successful antidepressant. Lundbeck invented a means of separating the racemic mixture and, upon testing each enantiomer, it was found that only the (+) enantiomer has the desired antidepressant effect. Lundbeck applied for, and was granted, a patent directed to the (+) enantiomer.

There was no dispute that Lundbeck was entitled to patent protection for its process of separating the (+) and (-) enantiomers. What was in dispute was Lundbeck’s claim to the (+) enantiomer per se. According to Generics, Lundbeck claimed the (+) enantiomer made by any method, whereas the patent specification itself only disclosed one way of making it and was therefore insufficient under the reasoning in Biogen. Applying Biogen, the High Court held that the patent was insufficient (i.e., claimed more broadly than the “technical contribution” of the invention merited). However, this was reversed on appeal on the basis that too broad a principle had been extracted from Biogen.


Generics appealed to the House of Lords maintaining that Biogen should be interpreted liberally and that the patent is therefore insufficient.

The claim of the Biogen patent was unusual in that it was directed to a product identified in part by how it was made and in part by what it did. The claim also covered a large number of embodiments. It was held to be invalid because it covered ways of “delivering the goods” within the scope of the claim that owed nothing to the teaching (“technical contribution”) of the patent.

In contrast, Lundbeck’s claim was a simple product claim to the (+) enantiomer only and, as such, Biogen was not relevant given the unusual nature and broad scope of the claim in that case.

The mistake of applying Biogen more widely than it should be was attributed to the focus in that case on inventive step, leading to “inventive step” or "inventive concept" being seen, incorrectly, as synonymous with "technical contribution to the art”.

All of the Lords were in agreement that the disclosure of the patent was sufficient. Lundbeck’s technical contribution was to make available the isolated enantiomer and so it followed that the claim to this enantiomer met the requirements for sufficiency, even though this means that, by finding one method of making a product, a person can obtain a patent for that product regardless of how it is made.