UK: Actavis V Eli Lilly - What Is "Normal Interpretation"?

Last Updated: 2 October 2017
Article by James Foster

In a landmark decision (Actavis v Eli Lilly), the UK Supreme Court has re-steered the law of patent infringement in the UK, stating that there is a doctrine of equivalents. But the doctrine need not be invoked if a variant infringes a claim "as a matter of normal interpretation".

The invocation of this so-called "limb (i)" test may have important consequences for validity squeezes in any particular case, and so its precise meaning is likely to prove contentious. In this article we consider how Lord Neuberger's limb (i) test may be expected to be applied.

Limb (i) infringement as defined in Actavis v Eli Lilly

As explained in our introductory article, in the Supreme Court's judgment in Actavis v Eli Lilly [2017] UKSC 48, Lord Neuberger, stated:

"...a problem of infringement is best approached by addressing two issues, each of which is to be considered through the eyes of the notional addressee of the patent in suit, i.e. the person skilled in the relevant art. Those issues are: (i) does the variant infringe any of the claims as a matter of normal interpretation [limb (i)]; 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 [limb (ii)]."

Lord Neuberger explained that while limb (ii) squarely raises the principle of equivalence in compliance with Article 2 of the Protocol on the interpretation of Article 69 of the European Patent Convention (EPC), the limbs balance the competing interests of the patentee and of clarity, as required by Article 1 of the Protocol. Both articles of the Protocol are set out in our introductory article here.

Limb (i), said Lord Neuberger, "self-evidently raises a question of interpretation", which is "familiar to all lawyers concerned with construing documents":

"While the answer in a particular case is by no means always easy to work out, the applicable principles are tolerably clear, and were recently affirmed by Lord Hodge in Wood v Capita Insurance Services Ltd."

Applying limb (i) to the facts of the Actavis v Eli Lilly case, there could be "no doubt" that according to normal principles of interpreting documents, the Actavis products (premetrexed free acid, pemetrexed ditromethamine, and pemetrexed dipotassium) did not infringe the patent, because they could not be said to fall within the expression "pemetrexed disodium".

However, infringement could still be found under limb (ii), which Lord Neuberger explained would normally have to be answered by reference to the facts and expert evidence. (The limb (ii) test is discussed in our next article).

Distinction between construction and infringement

Lord Neuberger emphasised repeatedly that the Protocol is not intended to be a guide to document construction. For example, he said:

"As Sir Hugh Laddie wrote in his instructive article Kirin-Amgen - The End of Equivalents in England? (2009) 40 IIC 3, para 68, "[t]he Protocol is not concerned with the rules of construction of claims" but with "determining the scope of protection".

The Protocol is, rather, a means to assist in the assessment of the question of infringement from case to case. He said it was very hard to be confident, from article 1, how far it was intended to permit a court to go beyond the actual language of a claim when interpreting a claim. Further:

"It is apparent from article 2 that there is at least potentially a difference between interpreting a claim and the extent of the protection afforded by a claim, and, when considering the extent of such protection, equivalents must be taken into account...".

In Lord Neuberger's view, the House of Lords' judgment in Kirin-Amgen v Hoechst [2004] UKHL 46 (which itself had followed Lord Diplock's analysis in Catnic, as applied by Hoffmann J in Improver), had erroneously conflated the issues of construction and infringement.

Although Lord Neuberger did not cite his own 2001 first instance judgment in the Kirin-Amgen case (Kirin-Amgen v Roche [2001] EWHC 518 (Pat)), which was overturned by the House of Lords, it seems he drew heavily upon its reasoning. In his 2001 judgment he explained that as a matter of principle, questions of construction of a claim in a patent, and questions of infringement of said claim are separate from each other, meaning there were dangers in determining issues of construction of the claims while having regard to the issues of infringement.

What is "normal interpretation"?

Returning to Actavis v Eli Lilly, when explaining the applicable principles "familiar to all lawyers concerned with construing documents", Lord Neuberger drew upon English contractual law as guiding the interpretation of a patent granted pursuant to the EPC. In Wood v Capita Insurance Services [2017] UKSC 24, Lord Hodge said:

"The court's task is to ascertain the objective meaning of the language which the parties have chosen to express their agreement. It has long been accepted that this is not a literalist exercise focused solely on a parsing of the wording of the particular clause but that the court must consider the contract as a whole and, depending on the nature, formality and quality of drafting of the contract, give more or less weight to elements of the wider context in reaching its view as to that objective meaning".

Article 2 of the Protocol on the interpretation of Article 69 prohibits the extent of protection being "defined by the strict, literal meaning" of the wording used in the claims.

In Improver v Remington [1990 F.S.R. 181, the case in which Hoffmann J first set out the Improver questions, Hoffmann J said:

"If the issue was whether a feature embodied in an alleged infringement which fell outside the primary, literal or acontextual meaning of a descriptive word or phrase in the claim ("a variant") was nevertheless within its language as properly interpreted, the court should ask itself the [Improver questions]" (emphasis added)

In Kirin-Amgen v Roche, Neuberger J (as he then was) construed the relevant claims of Kirin-Amgen's patent by interpreting them in the context of the teaching of the specification, and considering whether the conclusion he reached was in accordance with the evidence and the Protocol. Later, after concluding on the issue of validity, Neuberger J considered and answered the Improver questions in the context of his infringement analysis. (Note that by this point, the Court of Appeal had re-named the Improver questions the "Protocol questions").

When the Kirin-Amgen case reached the House of Lords, Lord Hoffmann criticised Neuberger J's approach. Lord Hoffmann did not consider the judge's approach to have been a "literal" construction as contemplated by the Improver/Protocol questions, of which he said:

"... to make any sense of the terms "primary, literal or acontextual meaning" in the Protocol questions, it must be taken to mean a construction which assumes that the author used words strictly in accordance with their conventional meanings."

Thus, whereas Lord Hoffmann would invoke the Protocol questions if an alleged infringement fell outside "the primary, literal or acontextual meaning of a descriptive word or phrase in the claim", the approach taken by Lord Neuberger, both at first instance in Kirin-Amgen v Roche and in Actavis v Eli Lilly, suggests that "normal interpretation" is neither a "strict, literal" interpretation (as prohibited by the Protocol) nor a "primary, literal or acontextual" meaning as contemplated in Improver.

This still begs the question of what "normal interpretation" means. Sir Hugh Laddie's 2009 commentary (Kirin-Amgen - The End of Equivalents in England? (2009) 40 IIC 3) is perhaps illuminative in this context.

Sir Hugh Laddie noted that in Kirin-Amgen the House of Lords described the law regarding patent construction in the UK before Catnic as "old English literalism", meaning acontextual literalism. Lord Hoffmann noted that following the change in commercial law in the 1970s, "[i]t came to be recognised that the author of a document such as a contract or patent specification is using language to make a communication for a practical purpose, and that a rule of construction which gives his language a meaning different from the way it would have been understood by the people to whom it was actually addressed is liable to defeat his intentions". The undesirable approach to construction was, according to Lord Hoffmann, the "old English literalism" which Lord Diplock had wished to avoid when taking a more purposive approach in Catnic, and which the Protocol questions were therefore designed to avoid.

However, Sir Hugh disagreed. He explained how, for the first 200 years of patents in England, there were no claims and so it was only the specification that could be considered. Once claims came into existence they were not as precise as is the practice today and they were always construed in the context of the specification. On the other hand, the English law approach to the interpretation of commercial documents in general was, until the 1970s, one of acontextual literalism in which surrounding materials could not be referred to as a guide to the interpretation of the contract. The House of Lords had, perhaps, fallen "into the error of assuming that old English literalism...had existed also in relation to the interpretation of patent claims". Sir Hugh said:

"The reason why the old acontextual approach applied to construing commercial documents but was never appropriate to construing patent claims was that in the case of the latter, unlike the former, the surrounding matrix, namely the specification, was an integral part - indeed historically the most important part - of the document of which the claims formed a part. There was no sensible way in which it could be ignored. In both cases the court simply looked at the whole document. In the case of patents that inevitably included the relevant context. In the case of commercial documents it did not."

This would seem to support an understanding that "normal interpretation" means a contextual literal construction, considering the skilled addressee's understanding of what the author meant by using those words in the context of the specification. This is neither a "strict literal" nor "acontextual" interpretation, because the claims are not read in isolation by relying purely on the dictionary meaning of the words. Yet while the approach is contextual or 'purposive' (in the sense of English contractual law), it is also 'literal' because the interpretation is confined to the technical embodiments of the concept as defined by the claims - the words used must be given a meaning, albeit a contextual one.

This approach would explain why Eli Lilly did not succeed on limb (i) despite the fact that the inventive concept of the patent was concerned with the pemetrexed anion generally, rather than being restricted to its disodium salt form - the Actavis products were not within the literal meaning of the words of the claim, even when construed contextually.

Does the reference to "literal meaning" in limb (ii) change this analysis?

Lord Neuberger said that when considering limb (ii) i.e. what it is that makes a variation "immaterial", a series of three questions (the reformulated Improver questions) can provide helpful assistance, although they remain only guidelines.

The 'reformulated Improver questions' are set out in our introductory article and will be discussed in more detail in our next article. The first begins "Notwithstanding that it is not within the literal meaning of the relevant claim(s) of the patent...". The third question also refers to the "literal meaning". It is apparent from the judgment that when Lord Neuberger here refers to the claim's "literal meaning", he is referring to the meaning which follows from the "normal interpretation" of the claim under limb (i).

Does this indicate that "normal interpretation" means the "literal meaning"? Or does it suggest something different?

Perhaps a good place to start, once more, is with the wording of the original Improver questions. As well as referring to "primary, literal or acontextual meaning" as part of the proviso for consideration of the questions, the reference within the questions (in original question 3) was to "the primary meaning" (i.e. would the reader skilled in the art nevertheless have understood from the language of the claim that the patentee intended that strict compliance with the primary meaning was an essential requirement of the invention? If yes, the variant is outside the claim).

It is consistent with the move from "primary, literal or acontextual meaning" (as per the proviso of the original questions) to "normal interpretation" (as per limb (i) of the reformulated questions) that the reference in original questions 3 to "primary meaning" has been adjusted also. This would seem to suggest that "literal meaning" in Lord Neuberger's reformulated questions does not mean the acontextual meaning of the words.

It would also be consistent with Lord Neuberger's approach to limb (i) if the reference to "literal meaning" in limb (ii) was to the contextual literal meaning of the language of the claim, this being the 'normal interpretation'.

However, whether the "normal interpretation" of Lord Neuberger's limb (i) does in fact mean the same thing as the "literal meaning" of limb (ii) remains open to question.

Why does it matter whether a variant infringes under limb (i) or limb (ii)?

Lord Neuberger noted that in contrast to limb (i), limb (ii) would normally have to be answered by reference to the facts and expert evidence.

If an alleged infringement or 'variant' can be shown to infringe pursuant to limb (i), there may, potentially, be scope for reducing the extent of expert evidence in a case regarding infringement. Usually the UK litigation system is geared towards a single substantive trial, but there is much flexibility. If the court were to agree to consider the question of limb (i) infringement as a preliminary issue, and concluded that there was infringement as a matter of "normal interpretation" of the claims, expert evidence in respect of limb (ii) could be avoided.

On the other hand, if infringement is established in accordance with limb (i), the extent of protection would equate conceptually with the scope of the claim for the assessment of a validity challenge. This enables squeeze arguments to be run, for example in accordance with the principle stated by the House of Lords in Biogen v Medeva [1996] UKHL 18 that the scope of a claim must be commensurate with the relevant technical contribution. This underlies many of the grounds on which the validity of a patent may be challenged.

Strategically, for patentees, it may be preferable for infringement to be established under limb (ii) than under limb (i). This is because if there is no infringement in accordance with the normal interpretation of the claim, but there is infringement under the doctrine of equivalents, the claim scope which the patentee may be called upon to defend as commensurate with the technical contribution would not necessarily need to encompass the infringement. Similarly the scope for potential anticipation arguments could be narrowed.

Whether there is indeed potential for a gap between the scope of the claim the subject of the validity challenge and the extent of protection afforded by the claim for infringement purposes is a question that the courts can be expected to be called upon to rule before too long. It will be discussed in a forthcoming article.

Is a "normal interpretation" test compliant with the EPC?

Can it be correct that in accordance with the EPC, the test for infringement is defined by reference to principles of English contractual law?

The EPC does not define the acts of infringement, for example of selling a product or using a process that falls within extent of protection of a patent claim. This remains a matter for national law, although the laws of EPC states have largely been aligned with the proposed Community Patent Convention - an early pre-curser to the (as yet unratified) Unified Patent Court. In the UK, the acts of infringement are defined in section 60 of the Patents Act 1960.

Article 69 provides that "[t]he extent of the protection conferred by a European patent or a European patent application shall be determined by the claims. Nevertheless, the description and drawings shall be used to interpret the claims".

The Protocol provides the gloss on the interpretation of this provision. While Article 69 clearly prevents patentees seeking a monopoly over something just because it is asserted in the specification, it is perhaps interesting that Article 69 does not say that the extent of protection shall be "defined by" the claims. Article 69 is in the Part of the EPC titled "Substantive Patent Law", and in the chapter titled "Effects of the European Patent and European Patent Application". In contrast, Article 84, which is in the Part titled "European Patent Application" and the Chapter titled "Filing and requirements of the European patent application", states that "[t]he claims shall define the matter for which protection is sought. They shall be clear and concise and be supported by the description".

Analysis of Lord Neuberger's test indicates that both limbs determine a question of infringement by consideration of the claims. Limb (i) uses the words of the claim neither as a guideline nor as defining a "strict" literal meaning - the latter because the "normal interpretation" requires the context, i.e. the description and drawings, to be taken into account, and not just where the claim language contains ambiguity. Limb (ii) takes account of elements which are equivalent to an element specified in the claims, as required in the Protocol, and again in accordance with the requirement that the extent of protection be "determined by" (i.e., by reference to) the claims, the description and drawings being used to interpret them.

Lord Neuberger's test, including limb (i), would indeed seem compliant with the EPC.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

To print this article, all you need is to be registered on

Click to Login as an existing user or Register so you can print this article.

Events from this Firm
19 Sep 2019, Seminar, Birmingham, UK

Providing GCs, Heads of Legal and senior in-house lawyers with timely, topical and practical legal advice on a variety of topics.

26 Sep 2019, Seminar, London, UK

Providing GCs, Heads of Legal and senior in-house lawyers with timely, topical and practical legal advice on a variety of topics.

8 Oct 2019, Seminar, Birmingham, UK

Supporting the development of paralegals, trainees and lawyers of up to five years' PQE by providing valuable knowledge and guidance together with practical tips.

Similar Articles
Relevancy Powered by MondaqAI
In association with
Related Topics
Similar Articles
Relevancy Powered by MondaqAI
Related Articles
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Mondaq Free Registration
Gain access to Mondaq global archive of over 375,000 articles covering 200 countries with a personalised News Alert and automatic login on this device.
Mondaq News Alert (some suggested topics and region)
Select Topics
Registration (please scroll down to set your data preferences)

Mondaq Ltd requires you to register and provide information that personally identifies you, including your content preferences, for three primary purposes (full details of Mondaq’s use of your personal data can be found in our Privacy and Cookies Notice):

  • To allow you to personalize the Mondaq websites you are visiting to show content ("Content") relevant to your interests.
  • To enable features such as password reminder, news alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our content providers ("Contributors") who contribute Content for free for your use.

Mondaq hopes that our registered users will support us in maintaining our free to view business model by consenting to our use of your personal data as described below.

Mondaq has a "free to view" business model. Our services are paid for by Contributors in exchange for Mondaq providing them with access to information about who accesses their content. Once personal data is transferred to our Contributors they become a data controller of this personal data. They use it to measure the response that their articles are receiving, as a form of market research. They may also use it to provide Mondaq users with information about their products and services.

Details of each Contributor to which your personal data will be transferred is clearly stated within the Content that you access. For full details of how this Contributor will use your personal data, you should review the Contributor’s own Privacy Notice.

Please indicate your preference below:

Yes, I am happy to support Mondaq in maintaining its free to view business model by agreeing to allow Mondaq to share my personal data with Contributors whose Content I access
No, I do not want Mondaq to share my personal data with Contributors

Also please let us know whether you are happy to receive communications promoting products and services offered by Mondaq:

Yes, I am happy to received promotional communications from Mondaq
No, please do not send me promotional communications from Mondaq
Terms & Conditions (the Website) is owned and managed by Mondaq Ltd (Mondaq). Mondaq grants you a non-exclusive, revocable licence to access the Website and associated services, such as the Mondaq News Alerts (Services), subject to and in consideration of your compliance with the following terms and conditions of use (Terms). Your use of the Website and/or Services constitutes your agreement to the Terms. Mondaq may terminate your use of the Website and Services if you are in breach of these Terms or if Mondaq decides to terminate the licence granted hereunder for any reason whatsoever.

Use of

To Use you must be: eighteen (18) years old or over; legally capable of entering into binding contracts; and not in any way prohibited by the applicable law to enter into these Terms in the jurisdiction which you are currently located.

You may use the Website as an unregistered user, however, you are required to register as a user if you wish to read the full text of the Content or to receive the Services.

You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these Terms or with the prior written consent of Mondaq. You may not use electronic or other means to extract details or information from the Content. Nor shall you extract information about users or Contributors in order to offer them any services or products.

In your use of the Website and/or Services you shall: comply with all applicable laws, regulations, directives and legislations which apply to your Use of the Website and/or Services in whatever country you are physically located including without limitation any and all consumer law, export control laws and regulations; provide to us true, correct and accurate information and promptly inform us in the event that any information that you have provided to us changes or becomes inaccurate; notify Mondaq immediately of any circumstances where you have reason to believe that any Intellectual Property Rights or any other rights of any third party may have been infringed; co-operate with reasonable security or other checks or requests for information made by Mondaq from time to time; and at all times be fully liable for the breach of any of these Terms by a third party using your login details to access the Website and/or Services

however, you shall not: do anything likely to impair, interfere with or damage or cause harm or distress to any persons, or the network; do anything that will infringe any Intellectual Property Rights or other rights of Mondaq or any third party; or use the Website, Services and/or Content otherwise than in accordance with these Terms; use any trade marks or service marks of Mondaq or the Contributors, or do anything which may be seen to take unfair advantage of the reputation and goodwill of Mondaq or the Contributors, or the Website, Services and/or Content.

Mondaq reserves the right, in its sole discretion, to take any action that it deems necessary and appropriate in the event it considers that there is a breach or threatened breach of the Terms.

Mondaq’s Rights and Obligations

Unless otherwise expressly set out to the contrary, nothing in these Terms shall serve to transfer from Mondaq to you, any Intellectual Property Rights owned by and/or licensed to Mondaq and all rights, title and interest in and to such Intellectual Property Rights will remain exclusively with Mondaq and/or its licensors.

Mondaq shall use its reasonable endeavours to make the Website and Services available to you at all times, but we cannot guarantee an uninterrupted and fault free service.

Mondaq reserves the right to make changes to the services and/or the Website or part thereof, from time to time, and we may add, remove, modify and/or vary any elements of features and functionalities of the Website or the services.

Mondaq also reserves the right from time to time to monitor your Use of the Website and/or services.


The Content is general information only. It is not intended to constitute legal advice or seek to be the complete and comprehensive statement of the law, nor is it intended to address your specific requirements or provide advice on which reliance should be placed. Mondaq and/or its Contributors and other suppliers make no representations about the suitability of the information contained in the Content for any purpose. All Content provided "as is" without warranty of any kind. Mondaq and/or its Contributors and other suppliers hereby exclude and disclaim all representations, warranties or guarantees with regard to the Content, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. To the maximum extent permitted by law, Mondaq expressly excludes all representations, warranties, obligations, and liabilities arising out of or in connection with all Content. In no event shall Mondaq and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of the Content or performance of Mondaq’s Services.


Mondaq may alter or amend these Terms by amending them on the Website. By continuing to Use the Services and/or the Website after such amendment, you will be deemed to have accepted any amendment to these Terms.

These Terms shall be governed by and construed in accordance with the laws of England and Wales and you irrevocably submit to the exclusive jurisdiction of the courts of England and Wales to settle any dispute which may arise out of or in connection with these Terms. If you live outside the United Kingdom, English law shall apply only to the extent that English law shall not deprive you of any legal protection accorded in accordance with the law of the place where you are habitually resident ("Local Law"). In the event English law deprives you of any legal protection which is accorded to you under Local Law, then these terms shall be governed by Local Law and any dispute or claim arising out of or in connection with these Terms shall be subject to the non-exclusive jurisdiction of the courts where you are habitually resident.

You may print and keep a copy of these Terms, which form the entire agreement between you and Mondaq and supersede any other communications or advertising in respect of the Service and/or the Website.

No delay in exercising or non-exercise by you and/or Mondaq of any of its rights under or in connection with these Terms shall operate as a waiver or release of each of your or Mondaq’s right. Rather, any such waiver or release must be specifically granted in writing signed by the party granting it.

If any part of these Terms is held unenforceable, that part shall be enforced to the maximum extent permissible so as to give effect to the intent of the parties, and the Terms shall continue in full force and effect.

Mondaq shall not incur any liability to you on account of any loss or damage resulting from any delay or failure to perform all or any part of these Terms if such delay or failure is caused, in whole or in part, by events, occurrences, or causes beyond the control of Mondaq. Such events, occurrences or causes will include, without limitation, acts of God, strikes, lockouts, server and network failure, riots, acts of war, earthquakes, fire and explosions.

By clicking Register you state you have read and agree to our Terms and Conditions