A well-established principle of English patent law was that construction for the purposes of validity should mirror that in respect of infringement.
Risking seven years bad luck, Arnold J smashed that mirror when he held that it is no longer good law that a patent claim will lack novelty simply because a prior publication discloses subject matter which, if performed, will necessarily infringe the claim. In particular, subject-matter that would infringe a claim applying the doctrine of equivalents will not suffice to deprive that claim of novelty.
This decision – in Generics (UK) Ltd and others v Yeda Research and Development Company Limited and others  EWHC 2629 (Pat) - marks the first patent court case to consider the impact on novelty of the UK doctrine of equivalents which was recently introduced into UK patent law by the Supreme Court in Actavis v Lilly  UKSC 48.
Claimants Mylan and Synthon (together the "claimants") sought revocation of European Patent (UK) No. 2 949 335 entitled "Low frequency glatiramer acetate therapy" of which the defendant, Yeda, is the registered proprietor and third party, Teva, is the exclusive licensee (together the "defendants").
The case is part of several rounds of proceedings between the parties concerning glatiramer acetate ("GA"), which Teva markets under the trade mark, COPAXONE. Worldwide sales of GA for 2016 were $4.2 billion, representing a fifth of Teva's worldwide sales and a "significantly higher percentage of Teva's profits" (see  EWHC 2629, 6).
The basic patent protecting GA expired in May 2015. The patent in suit is directed to a 40 mg dosage regimen of GA administration to patients suffering from relapsing forms of multiple sclerosis (the "Patent"). The claimants had previously introduced a 20 mg GA generic product but were now seeking to clear the way for the launch of a 40 mg GA generic, for which they had received marketing authorisation on 5 October 2017. If the Patent were valid, there was no dispute that the claimants' intended acts would infringe it.
Novelty challenge under the doctrine of equivalents
How the UK Supreme Court's newly articulated doctrine of equivalents would apply to the assessment of validity has been debated since the UK Supreme Court's judgment in Actavis v Lilly in July 2017. As the issue was not addressed in Actavis, Arnold J noted that a further Supreme Court decision would be required to provide a definitive answer. In the meantime, the judge decided that prior art subject matter, which would infringe the claim applying the doctrine of equivalents, would not suffice to destroy novelty.
Before reaching this conclusion, Arnold J had to decide how the patent claims should be construed. Before Actavis, it was settled law that claims should be construed in the same way (at that time, purposively) for the purpose of assessing both novelty and infringement.
The claimants, seeking revocation of the patent, submitted that this long standing principle of mirroring construction for validity and infringement should remain. In their view, the patent lacked novelty because it was enough that the prior art disclosed subject matter that would infringe the claim applying the doctrine of equivalents, even if that subject matter would not fall within the claim on its 'proper' interpretation.
The defendants disagreed, submitting that it was no longer the law that a claim lacked novelty if the prior publication disclosed subject-matter which, if performed, would necessarily infringe the claim. They argued that a claim would only lack novelty if the subject matter in the prior art fell within the claim on its proper interpretation, arguing that:
- the leading authority on infringement and disclosure, Synthon v SKB  UKHL 59, had not been considering the question of anticipation by equivalents, because at that time it was not possible to infringe by virtue of being an equivalent;
- it is established jurisprudence of the EPO Boards of Appeal that a claim is not deprived of novelty by an obvious equivalent of a feature in a prior publication; and
- the Supreme Court’s decision in Actavis concerned infringement and scope of protection, not validity.
Arnold J agreed with the defendants but nevertheless went on to consider that, if he was wrong and the doctrine of equivalents did apply to validity, the prior art disclosure would have deprived the claims of novelty.
As noted by the claimants, Arnold J's decision could result in a situation where a claim is infringed, applying the doctrine of equivalents, by a person who is performing exactly that which is taught by the prior art, yet the claim is novel over that prior publication. This initially sounds frightening, but in most cases the alleged infringer would have two defences in these circumstances (as set out in Gillette Safety Razor v Anglo-American Trading  30 RPC 465):
- If the claim scope covers the prior art and therefore the actions of the defendant, the patent must be invalid because it would be obvious in light of the prior art.
- If the claimant argues a narrow construction of the claims of the patent in suit, to avoid the prior art, the alleged infringer's embodiment would fall outside the claims of the patent in suit.
An interesting question is what would happen if those two defences are not available because the only attack available to the person working the earlier invention is a novelty only attack under s2(3) of the Patents Act 1977? A person in this scenario could be at risk of infringing the later patent by working an earlier invention. This is a significant departure from the previous position, where it has always been the case that a person doing no more than performing the prior art will not infringe.
In this case, Arnold J ultimately held the claims invalid for obviousness in light of an alternative regimen disclosed by the prior art (the same prior art over which the claims were found to be novel), meaning that the claimed regimen was obvious to try with a fair expectation of success.
It is clear that practitioners must now consider claim construction separately for validity and infringement. When it comes to validity, claim scope will be determined by the proper interpretation of the words used in the claim. For infringement, the scope of protection may go beyond the normal interpretation of the words by virtue of the doctrine of equivalents. This disjunctive approach is rather alien to patent lawyers and somewhat surprising given the historic practice of the English courts. It had previously been desirable to try infringement and validity issues together on the basis it is all too easy for a patentee to argue a narrow interpretation of the claim when defending its validity but an expansive interpretation when asserting that very same claim. It appears that this new approach is now permitted and inevitable. However, given the limited factual scenarios in which a claim could be valid over prior art subject matter which is later alleged to infringe, there are questions as to how often this shift in principle will dictate the outcome of future cases.