In 2017 the U.K. Supreme Court issued its landmark ruling in Actavis v Eli Lilly , that fundamentally changed how U.K. patent infringement is assessed, by the (re-) introduction of a ‘doctrine of equivalents’, in which a feature that falls outside of a ‘normal’ interpretation of the claims but that nonetheless varies from the invention in a way that is ‘immaterial’, infringes a U.K. patent. This can provide a U.K. patent with a broader scope of protection than was the case prior to the Actavis decision.
This article looks at how the Actavis decision has been applied and developed in subsequent decisions by the U.K. courts.
The Actavis decision – The dawn of a new era for patent infringement in the U.K.
To recap - prior to the Actavis decision, the scope of protection of a U.K. patent was assessed using a ‘purposive approach’, namely ‘what the person skilled in the art would have understood the patentee to be claiming’.
However, in Actavis Lord Neuberger reverted back to first principles, namely the text of Art. 69 of the European Patent Convention (EPC) and the Protocol on its Interpretation, the latter of which states that ‘due account shall be taken of any element which is equivalent to an element specified in the claims’.
This, said Lord Neuberger, meant that the following two limbed approach should be used:
i. does the variant infringe any of the claims as a matter of normal interpretation; and, if not,
ii.does the variant nonetheless infringe because it varies from the invention in a way or ways which is or are immaterial?
If the answer to either issue is "yes", there is an infringement; otherwise, there is not."
The first limb of this approach has been held to require the application of the normal principles of interpreting documents.
The second limb of the approach requires a consideration of what ‘immaterial’ means, and the decision in Actavis set out that the following three ‘Actavis questions’ are to be used as guidelines to do this (which are a reformulation of the questions used prior to Actavis, using the old ‘purposive approach’):
1) Notwithstanding that it is not within the literal meaning of the relevant claim(s) of the patent, does the variant achieve substantially the same result in substantially the same way as the invention, i.e. the inventive concept revealed by the patent?
2) Would it be obvious to the person skilled in the art, reading the patent at the priority date, but knowing that the variant achieves substantially the same result as the invention, that it does so in substantially the same way as the invention?
3) Would such a reader of the patent have concluded that the patentee nonetheless intended that strict compliance with the literal meaning of the relevant claim(s) of the patent was an essential requirement of the invention?
In order to establish infringement in a case where there is no literal infringement, a patentee would have to establish that the answer to the first two questions was "yes" and that the answer to the third question was "no".
This (re-) introduction of a doctrine of equivalents can assist proprietors in protecting immaterial variants.
Actavis also opened the door for reference to be made to what was said in the prosecution history of a patent application, when assessing the scope of a claim, although this can only be done in limited circumstances.
Decisions post-Actavis – the development and solidification of a doctrine of equivalents in U.K. law
The doctrine of equivalents, that was (re-) introduced in Actavis, has been developed by subsequent U.K. cases, in particular in terms of the interpretation and application of the first and second limbs of the Actavis approach, and the three Actavis questions.
The first limb of the Actavis approach
The meaning of ‘normal interpretation’ in the first limb of the Actavis approach has been considered in detail and elaborated upon, retaining the old ‘purposive approach’ (this has been held to be without the use of the ‘Improver questions’ that were previously used to assess this, although this is not settled, as observed in Icescape and Liqwd v L’Oreal)).
The second limb of the Actavis approach
In Icescape v Ice-World , Lord Kitchin indicated that, when assessing what ‘immaterial’ means (in the second limb of the Actavis approach), the three Actavis questions should be considered the mandatory approach and not just guidelines (as had previously been stated in Actavis). This may permit less flexibility in the assessment of what ‘immaterial’ means. However, Lord Neuberger’s judgement remains the authority on this point.
Lord Kitchin also interpolated ‘literal’ in the first Actavis question to mean ‘normal’, i.e. not an acontextual literal interpretation (i.e. not a literal dictionary definition, without any consideration of the context), which has provided useful clarity in this respect.
In the years since Icescape v Ice-World , the doctrine of equivalents has been solidified in U.K. law and developed. Some notable cases are discussed below.
In Regen v Ester [HC; 2019] it was held that, when applying the doctrine of equivalents, numerical claims should be treated in the same way as any other claim. Interestingly it was found that although a numerical limitation in a claim (to 0.10 M sodium citrate) did not cover the alleged infringement (that used 0.136 M sodium citrate) using the principles of normal interpretation, a reader of the patent would not have concluded that the patentee intended that strict compliance with the literal meaning of the claims was an essential requirement of the invention and so this was held to be an infringement. This highlights that, following Actavis, the focus when determining the scope of a patent for the purpose of infringement is now on the ‘inventive core’ of a patent.
This principle of now focussing on the ‘inventive core’ of a patent has also been followed in various other decisions, including Marflow v Cassellie  and Technetix v Teleste .
In Illumina Cambridge Ltd v Latvia MGI Tech SIA & Ors , it was held that the wording used in the description could be taken into account when considering the third Actavis question, namely whether a reader of the patent would have concluded that the patentee intended that strict compliance with the literal meaning of the claims was an essential requirement of the invention.
In this respect, in L’Oreal v RN Ventures [HC; 2017] it was held that the feature in issue was an ‘immaterial variant’, as it produced substantially the same result in the same way as in the patent, and it would have been obvious to the skilled person that this was the case (the first and second Actavis questions). However it was held that, although the variant was discussed at great length in the patent specification, the Patentee nonetheless chose to exclude it from the claims. Therefore a reader of the patent would have concluded that the patentee intended that strict compliance with the literal meaning of the claims was an essential requirement of the invention (the third Actavis question) and so it was held that the variant was not an equivalent.
Although the judge made it clear that this case turns on its own facts, this may indicate a future direction, that the courts could take, that reduces the effect of the Actavis decision. In this respect, if courts generally hold that strict compliance with the literal meaning of the claims was an essential requirement of the invention (the third Actavis question (3)), then this would reduce the findings of infringement by an ‘immaterial variant’, thereby lessening the impact of Actavis.
A detailed consideration of the impact of the Actavis decision on the assessment of validity of a U.K. patent is outside of the scope of this article.
However, it has been held that the doctrine of equivalents does not apply for the assessment of validity (i.e. of novelty).
Furthermore, this difference in the assessment of the scope of patent for validity and infringement has resulted in decisions concerning how/if there can be a possible extension of a ‘squeeze’ argument defence (the ‘Gillette’ defence) available under the prior purposive approach, to apply to equivalents.
It is clear that, following Actavis, the (re-) introduction of a doctrine of equivalents in U.K. law has been firmly established in the assessment of infringement of a U.K. patent. The doctrine of equivalents can provide for the protection of immaterial variants that may not have been covered under the prior purposive approach, and aligns the U.K. law of infringement more closely with that of other major EPC jurisdictions (e.g. Germany).
Following Actavis, a number of cases have put a focus on the ‘inventive core’ of a patent, thereby resulting in the finding of infringement by ‘immaterial variants’. However, other cases have indicated a reluctance to apply a doctrine of equivalents too generally, by holding that strict compliance with the literal meaning of the claims was required, under the third Actavis question, thereby lessening the impact of Actavis.
It will be interesting to see how this develops going forward.
This article is provided for general informational purposes only and is not legal advice.
 Catnic Components Ltd v Hill & Smith Ltd  RPC 183, Improver Corpn v Remington Consumer Products Ltd  FSR 181 and Kirin-Amgen Inc v Hoechst Marion Roussel Ltd  RPC 9.
 Article 2 – The Protocol on Interpretation of Article 69 EPC
 Wood v Capita Insurance Services Ltd  UKSC 23
 (Generics v Yeda ; Actavis v ICOS ; Icescape v Ice-World ; Regen v Estar ;, Illumina v Premaitha  and Liqwd v L'Oréal ).
 Generics v Yeda [HC; 2017], Facebook v Voxer [HC; 2021]