It's always a little disappointing when you hope that an appeal will be decided on one ground and find that it can comfortably be disposed of on quite another one. That's what happened in Edwards Lifesciences AG v Cook Biotech Inc. A year ago (here), Mr Justice Kitchin heard a dispute over Cook's European patent (UK) 1255510, “stent” valves”, for an artificial heart valve within a radially expandable stent which can be delivered through a catheter. Edwards applied to have the patent revoked, while Cook counterclaimed for infringement. The main issue at the trial --apart from a couple of minor feeble arguments about insufficiency and added matter -- was whether the patent was novel and inventive over a succession of cited documents. According to the judge, the patent as a whole was obvious in light of one of these documents, which had been published before the priority date of the patent. The judge then considered the effect of a further document, this being a scientific paper published between the claimed priority date and the application date of the patent -- which would only be relevant if the priority claim was invalid. The application from which priority was claimed was a US provisional, filed in the names of three inventors, of whom only one was employed by Cook Biotech at the time. A PCT application was then filed one year later, in the name of Cook Biotech. The other two inventors' rights were not assigned to Cook until substantially later, after the PCT application entered the European regional phase. According to Edwards, Cook had not derived the right to claim priority because, at the time the application was made, the right had not been assigned to it: Cook was therefore only successor in title for one inventor, via a contract of employment.
Citing sections 5 and 7 of the UK Patents Act 1977, Article 8 of the Patent Co-operation Treaty and Article 4 of the Paris Convention (which section 5 is intended to put into effect in the UK), Kitchin J came to the logical conclusion (at para.95 of his judgment) that the effect was clear:
"A person who files a patent application for an invention is afforded the privilege of claiming priority only if he himself filed the earlier application from which priority is claimed or if he is the successor in title to the person who filed that earlier application. If he is neither the person who filed the earlier application nor his successor in title then he is denied the privilege. Moreover, his position is not improved if he subsequently acquires title to the invention. It remains the case that he was not entitled to the privilege when he filed the later application and made his claim. Any other interpretation would introduce uncertainty and the risk of unfairness to third parties ..."The scientific paper was therefore prior art, which would thus render some of the claims invalid for lacking an inventive step over it. Cook appealed.