Eli Lilly and Company v Actavis UK Limited Supreme Court Ruling
13 July 2017
Yesterday morning the UK Supreme Court released its judgment in the ongoing Actavis/Eli Lilly saga, which is likely to have significant implications in the interpretation of claim scope during infringement proceedings, and explicitly embeds prosecution file estoppel into UK patent law.
The judgment clearly places the consideration of equivalents that work in the same way as the invention, but fall outside the strict literal wording of the claims, foremost when determining the scope of protection.
The judgment,  UKSC 48
, may also have consequences upstream in the patent application process and influence commercial decisions during prosecution.
Below we highlight the significant points from the decision and our initial thoughts on the possible consequences, with more to follow when we have considered the full implications of this important ruling.
Eli Lilly has granted claims to the Swiss-style medical use of a specific salt of pemetrexed and vitamin B12 for the treatment of cancer. It is important to note that the actual inventive concept resides in the combination of vitamin B12 and pemetrexed, which renders the otherwise toxic pemetrexed suitable for use in a therapeutic composition. The specification was drafted accordingly, and the prosecution history showed a narrowing of claims from a very broad functional definition of the active agent that encompasses pemetrexed, to the specific salt of pemetrexed, to address objections of lack of support and added matter.
Actavis sought a declaration of non-infringement for three products which comprise different salts of pemetrexed and vitamin B12. After previous findings of non-infringement in the High Court and Court of Appeal, the Supreme Court, by effectively invoking the doctrine of equivalents, found that Actavis’ products do infringe Eli Lilly’s patent, based on a non-literal interpretation of the claim.
Reformulation of the Improver test for determining infringement
In a departure from the top-level principle-led approach to claim construction extolled by the Supreme Court in Kirin-Amgen and others v Hoechst Marion Roussel Ltd and others,  UKHL 46, the tribunal has, in effect, returned to a more structured approach to non-literal infringement introduced in Catnic Components Ltd v Hill & Smith Ltd  RPC 183 and subsequently developed in Improver Corp v Remington Consumer Products Ltd  RPC 69.
In doing so, the Court reconsidered Question (2) of the Improver questions and reformulated the latter to impart knowledge on the skilled person at the priority date, which in some cases may not actually have been realised until years later. This is in stark contrast to the knowledge that the skilled person has for the assessment of patentability during patent prosecution.
The question to ask now, when determining infringement, should be whether the skilled person, at the priority date and knowing that the variant does work, would consider it obvious that the variant achieves substantially the same result in substantially the same way as the invention, i.e. is it obvious that the variant (that works) is making use of the claimed inventive concept. Construed in this manner, a claim may capture not only variants envisaged at the time of filing the application, but also variants that may have been developed years later, but which, now knowing that they work, would be considered to use the inventive concept of the patent when viewed at the priority date.
Such an approach has clear implications in situations where particular variants were envisaged as part of the invention at the time of filing, but were excluded from the claims due to, for example, a lack of supporting data. The reformulation of the second Improver question essentially resolves this lack of support since now the skilled person knows that the variant works.
This may now allow a granted claim to capture those variants for which support was lacking and were excised during prosecution. In view of this, applicants may therefore wish to reconsider the value of an otherwise narrow and commercially unattractive claim for which a broad claim scope is unsupported but technically plausible.
Similarly, the Judgment may have implications for drafting practice. For instance, it may be beneficial to draft a specification broadly even in cases where an applicant wants to protect a very narrow embodiment, dependent on the known prior art.
Embedding file estoppel in UK patent law
Although the Court in this case did not consider the file history to be relevant, based on the amendments made and the reasons behind them (i.e. lack of support and added matter), it did state that the file history might, legitimately, be consulted where either a) the point at issue is truly unclear when confined to interpretation from the patent specification; or b) it would be contrary to the public interest for the contents of the file to be ignored.
We can only take “contrary to the public interest”
to mean cases where there has been a clear statement or amendment during prosecution that excludes subject matter not literally encompassed by the claims, for instance when addressing a lack of novelty objection.
It seems clear then that there are circumstances in which one’s past decisions, statements, and amendments could be used against the patentee.
For more information, please contact your normal Potter Clarkson representative