Patent Revocation [United Kingdom]

The UK Patents Court rendered a judgment in Ivax Pharmaceuticals (UK) Ltd v Chugai Seiyaku Kabushiki Kaisha [2006] EWHC 756 (Pat), conveniently posted here on BAILII.Chugai owned a patent for a method of producing a pharmaceutical preparation containing nicorandil, used for treating angina. Claim 1 of the patent described a method of producing a stable nicorandil preparation by mixing nicorandil with a saturated higher aliphatic acid or a saturated higher alcohol, both of which were solid at room temperatures. Ivax sought revocation on the ground of lack of inventive step.

Chugai denied that its patent was invalid but (i) nonetheless applied to amend it, saying that the proposed amendment was only intended to distinguish the invention further from the cited art and (ii) counterclaimed that Ivax was infringing. Ivax opposed the amendment on the ground that it added matter over the application as originally filed, contrary to section 76(3)(a) of the Patents Act 1977.

Kitchin J allowed Ivax's revocation claim.
* In considering whether a proposed amendment contained added matter, such matter would be regarded as additional unless it was clearly and unambiguously disclosed in the application as originally filed - even though that disclosure might be implicit.

* On the evidence, the unamended patent was invalid for lack of inventive step: Chugai's problem was that the claims were not limited to the technical advance that it had made, but instead covered work that would have been plainly technically obvious to the skilled person.

Law Wire is pleased to see how cautious the UK courts are when it comes to allowing applications to amend granted and litigated patents. They guard against the danger of moving the goalposts, while allowing amendments that help the players work out exactly where the goalposts are.

Rodney D. Ryder