Yesterday evening, Fieldfisher joined some 800 other members of the patent community to listen to a panel of European and US judges debate the recent UK Supreme Court decision in Actavis UK Ltd v Eli Lilly & Co which introduced a doctrine of equivalents into UK law. The panel included two of the judges who decided the case in the Supreme Court, Lords Neuberger and Sumption, as well as Professor Dr Peter Meier-Beck, Presiding Judge of the German Federal Court of Justice, Judge Rian Kalden, Head of the IP Division, Court of Appeal, The Hague and Judge Kate O’Malley, US Court of Appeals for the Federal Circuit. The panel was chaired by Professor Sir Robin Jacob who explained that Lord Hoffman was unable to join the panel.
Here is a note of the key issues.
Is there a free standing doctrine of equivalents in the UK now?
Lord Neuberger made it clear that we do have a law of equivalents "because that is what the EPC says". Lord Sumption agreed.
Prosecution history estoppel
The doctrine of prosecution history estoppel would have been a complete answer to the case in the US, Judge Kate O'Malley said. The claim would not have extended beyond pemetrexed disodium. This was in light of the patentee's acceptance of a claim limitation to that particular salt during examination.
As for the UK, Lord Sumption reiterated the Supreme Court's decision: the courts will only look at the prosecution history in exceptional circumstances. This applies to UK/EPO history as well as statements made before overseas patent offices.
Judge Kate O'Malley said that the US does not look at the file history from outside the US: "We don’t understand enough about practices in other offices to take those files into account".
Dr Peter Meier-Beck, agreeing with Lord Hoffman's position in Kirin Amgen, thought that "life is too short" to consider the file.
"The examiner was hopelessly wrong"
Lord Neuberger agreed with this statement of Sir Robin about the examination of the pemetrexed patent.
We do not think this should be taken into account when determining the scope of protection. Judge Kate O’Malley made clear that, faced with a claim limitation during US examination, patentees have a choice: appeal the examiner's decision or accept the limitation. If the patentee chooses the latter, they must live with it. The doctrine of equivalents cannot be applied to reclaim scope surrendered during prosecution.
How would Improver be decided today?
Lord Neuberger confirmed what many had thought: "I suspect Improver would have been decided differently today".
How would Kirin-Amgen be decided today?
Lord Neuberger indicated that if Kirin-Amgen arose in the Supreme Court today, he would say that Neuberger J was wrong at first instance. This was in response to Sir Robin's report that the President of the Dutch court had described the "Pemetrexed Case" as "Neuberger's revenge".
Lord Neuberger commented that, in respect of DNA patents, we are in slightly odd territory. He accepted that the Kirin-Amgen variant may not have been an infringing equivalent.
Effect of equivalents on validity
The US position is that patent scope cannot cover equivalents which would have been old or obvious at the priority date. The US "ensnarement doctrine" means that a patent cannot read onto something that was in the prior art or that could not have been patented. Judge Kate O'Malley made it very clear that the doctrine of equivalents survives in the US but is contained by the countervailing principles of file wrapper estoppel and ensnarement.
In Generics v Yeda and Teva  EWHC 2629 (Pat), the first case to apply the UK doctrine of equivalents, Arnold J said that "it is no longer the law that a claim lacks novelty if the prior publication discloses subject matter which if performed, would necessarily infringe the claim".
Numerical limits do not lend themselves to general rules
Express numerical limitations in a claim could be considered by the courts as reflecting a clear intention that the patentee did not intend to go outside those limits. Lord Neuberger thought that much will depend on reading the claim in light of the specification. It may not be possible to lay down a general rule; context is key. This inquiry would engage question 3 of the modified Improver analysis.
Judge Kate O'Malley said that "very often" there are reasons for numerical limits, usually because they read on the prior art. The US courts do not see many claims, under the doctrine of equivalents concerning numerical cases. There are exceptions; the doctrine might cover an equivalent as long as the numerical limitations were not critical to the inventive concept. In those cases, there would be a question as to how far one can go outside the numerical limit.
The German and Dutch judges agreed that the decision in the "Pemetrexed Case" is a positive step closer to a harmonised approach to equivalents in Europe (particularly as the UPC is still eagerly awaited).