The five judges unanimously ruled that Article 57 of the EPC does not require patent applications for new genes to provide evidence of clinical tests to show industrial application.
Article 57 says that an invention is susceptible of industrial application if it can be made or used in any kind of industry, including agriculture.
In one of the opinions, Lord Hope said the standard set by the Court of Appeal was "a more exacting one than that used by the Technical Board of Appeal [of the EPO]". Unlike the UK courts, the TBA had allowed HGS’s patent.
"He [Lord Justice Jacob, who wrote the Court of Appeal opinion] appears to have been looking for a description that showed that a particular use for the product had actually been demonstrated rather than that the product had plausibly been shown to be ‘usable’," wrote Hope.
Meanwhile, Lord Neuberger said that "the basis upon which the Judge [Mr Justice Kitchin] decided the issue was not consistent with the approach adopted by the Board".
The five judges appeared reluctant to overturn the two decisions of the lower courts, which were consistent with each other and both authored by patent specialists based on extensive evidence in the trial court.
But, as Lord Walker argued, there were two points of principle that favoured their interpretation: first, to reduce the risk of a chilling effect on investment in bioscience and second to align the UK’s interpretation of the EPC with that of other contracting states.
"To my mind these considerations justify this Court in taking what would otherwise be a questionable course."
Lord Neuberger, who wrote the main judgment, has a lot of experience in patent law. "It is plainly appropriate in principle, and highly desirable in practice, that all these tribunals interpret the provisions of the EPC in the same way," he said.
He argued that there should be "room for dialogue between a national court and the EPO" but added: "Nonetheless, where the Board has adopted a consistent approach to an issue in a number of decisions, it would require very unusual facts to justify a national court not following that approach."
He also argued that requiring clinical tests to show industrial application would be expensive and time-consuming and it would be hard to keep them confidential.
But he said the Board’s approach in these types of cases is "tolerably clear" and the "hurdle for patentability" should not be set too high".
"I appreciate that the dividing line between ‘plausibility’ and ‘educated guess’, as against ‘speculation’, just like the contrast between ‘a real as opposed to a purely theoretical possibility of exploitation’, can be difficult to discern in terms of language and application, and is a point on which tribunals could often differ," wrote Neuberger.
The case will now be sent back to the Court of Appeal for further hearings.
However, it is not yet clear when these will be heard or by whom. The leading patent specialist in the Court of Appeal is Kitchin, who is automatically disqualified. Lord Neuberger, who wrote the leading Supreme Court opinion today, also normally sits in the Court of Appeal.