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House of Lords clarifies law on inventive step
In Conor v Angiotech, this week the UK House of Lords reviewed a basic issue in patent law: how to determine whether the concept described in the patent involves an "inventive step" and is consequently entitled to protection. Although this question - whether the invention is obvious - might appear to be simple it seems to have caused courts and patent offices throughout Europe and elsewhere tremendous difficulty.
Lord Hoffmann said that national courts across Europe and the European Patent Office (EPO) should interpret the EPC in a uniform way as far as possible. He recognised that, nevertheless, inconsistent decisions may occur owing to differences in procedure and evidence .
Correct identification of the inventive concept is crucial
In this case the High Court and Court of Appeal had held Angiotech's patented invention was obvious and, therefore, the UK patent was invalid, whereas the Dutch court had held that it did involve an inventive step. However the difference arose because of differing approaches to identifying the inventive concept to be examined. Lord Hoffmann and his colleagues preferred the Dutch approach to identification of the concept and upheld Angiotech's appeal.
Look at the claim
The claim in issue related to a stent coated with the anti-angiogenic drug taxol for the treatment of restenosis. (Restenosis is a re-narrowing of the artery or other vessel as a result of excessive cell growth which sometimes occurs after a stent has been inserted to widen the vessel.)
The Court of Appeal noted that the patent contained little or no experimental data to show that taxol worked. That being so the invention was merely a proposal the taxol might work. This was little or no advance over what had previously been proposed and was obvious.
Lord Hoffmann said this was the wrong approach. The invention should not be determined by "some vague paraphrase based upon the extent of (the patentee's) disclosure in the description". In deciding what the inventive concept was, one simply looked at the claim - after all the purpose of the claims is to define the invention. The prior art had not identified taxol as suitable - in fact there were concerns about its safety. The lack of information in the patent as to how a suitable stent might be made "had nothing to do with inventive step" ; the only relevance of this was to insufficiency or whether the claims were supported by the description which were not issues in this case. The invention was the use of a taxol-coated stent to prevent restenosis. This was not obvious.
No need to prove the invention works
There was not, as others had suggested, a requirement for the patent specification to demonstrate that the invention would work or explain why; the EPC requires the claims to be supported by the description but this is not related to the inventive step requirement. The lower courts' view that the specification did not contain sufficient evidence that taxol was particularly suitable had led them to conclude (wrongly) that the inventive concept was only the idea of trying taxol to see if it worked (which would have been obvious from the prior art).
The significance of the judgment
The approach to inventive step is attractive for its clarity and simplicity. It avoids the complicated approach sometimes adopted and may also, as one consequence, lead to a more patent friendly approach to obviousness in the UK.
9 July 2008 Conor Medsystems Inc v Angiotech Pharmaceuticals Inc and The University of British Columbia [2008] UKHL 49.