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House of Lords clarifies the UK's approach to insufficiency


1 May 2009


A patent, to be valid, must be sufficient. To be sufficient, the specification as a whole must enable the skilled man to perform the invention using his or her skill or knowledge, allowing for ordinary trial and error.

This can be difficult in practice. Often, an invention lies not in the discovery of a product, but rather in the first method of creating a known product. What if in showing one such method, a claim of the patent claims the product? Does the claim lack validity for insufficiency?

Biogen v Medeva concerned the invention of a method of making artificially constructed DNA molecules which, when introduced into a host cell, would cause that cell to make antigens of the hepatitis B virus. Whilst the inventive step was the method applied, the patent claimed – in part - the product created.

Lord Hoffmann held the claim in question to be invalid for insufficiency. He stated that such a claim will be invalid where it claims “every way of achieving a result when it enables only one way and it is possible to envisage other ways... care is needed not to stifle further research and healthy competition by allowing the first person who has found a way of achieving an obviously desirable goal to monopolise every other way of doing so.”

‘Biogen insufficiency’ therefore became the accepted principle that, where the inventive concept is not a thing but a way of making a thing that the art knew it wanted to make, a claim not limited to that method will be insufficient.

In the recent case of Generics v Lundbeck, the patent claimed products and processes relating to the antidepressant drug escitalopram, for which the closest prior art was citalopram. Whereas citalopram is a racemate comprising (+) and (-) enantiomers, escitalopram comprises the pure (+) enantiomer. The inventive step therefore lay in finding a way to separate the enantiomers. Importantly, the resultant product did not itself lack novelty nor was obvious. However, the Claimants also contended that the product claim was ‘Biogen insufficient’. At first instance Justice Kitchin agreed, applying Biogen.

The Court of Appeal took a different view. Lord Hoffman (unusually coming down from the Lords to deliver the leading Judgment) distinguished his decision in Biogen, asserting:

“In an ordinary product claim, the product is the invention. It is sufficiently enabled if the specification and common general knowledge enables the skilled person to make it. One method is enough.”

Lord Hoffmann noted that Biogen concerned a “product-by-process” claim, so formulated because a simple product claim would have lacked novelty. It had been therefore treated as a class, which naturally could result from a wide variety of possible processes. In disclosing only one such process, it failed for insufficiency.

The case then went to the House of Lords, presenting the intriguing possibility of a ruling that the interpretation given by Lord Hoffman (who could not sit, having sat in the Court of Appeal) of his own decision in Biogen had been incorrect. Fortunately or unfortunately, the House of Lords declined to do this. The leading Judgment of Lord Neuberger agreed that, where a product is claimed, the disclosure of one method of making that product will render the claim sufficient. In doing so he addressed the objection that the patentee is thereby obtaining a monopoly exceeding his technical contribution to the art:

“…to put it at its lowest,…the respondent's technical contribution in this case was to make available, for the first time, a product which had previously been unavailable, namely the isolated (+)-enantiomer of citalopram. On that basis, it would appear to follow that the respondent was entitled to claim the enantiomer.”

The decision is interesting, in that Lord Hoffmann has effectively confined the ratio in Biogen to its somewhat esoteric facts. However, the decision also follows the line consistently adopted by the Lords in recent decisions (including Conor Medsystems Inc v Angiotech Pharmaceuticals Inc), in stating that the inventive concept is the product or process as claimed, not some abstract concept construed from the claim. Such a “vague paraphrase” is capable of being much wider than the actual wording, thereby subjecting it to charges of lack of novelty, obviousness, or insufficiency that the wording itself does not warrant.

This article was first published in WIPR

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