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In many jurisdictions, the scope of protection afforded by a patent is defined by the claims as read either literally or under doctrine of equivalents.  Infringement based on the doctrine of equivalents may be based in part on statutory law, the interpretation of which is generally established via case law (e.g. Court decisions).  The purpose of the doctrine of equivalents is to promote fair patent coverage so that trivial departures (e.g., variants or deviations) from the claim language cannot be used to avoid infringement. 

This is the fifth post in our series examining the law governing the doctrine of equivalents in several European countries.  Our first post examined the law governing the doctrine of equivalents in Spain, our second post examined the law in the Netherlands, our third post examined the law in Germany, and our fourth post examined the law in Denmark.  These posts can be viewed here:  Doctrine of Equivalents – Spain, Doctrine of Equivalents – the Netherlands,  Doctrine of Equivalents – Germany and Doctrine of Equivalents – Denmark.

Doctrine of Equivalents in the United Kingdom


The United Kingdom (UK) is one of the top jurisdictions in the world for patent enforcement.  Most patent cases are brought in the Patents Court, a specialized court based in London that is part of the High Court of Justice.  Also available is the Intellectual Property Enterprise Court (IPEC) which handles smaller, less complex disputes.  Regardless, there are no jury trials available in either court.  Patent cases in the High Court tend to move relatively quickly, normally taking between nine to 12 months to go to trial, although in more complex lawsuits, the time to trial can take 18 months to two years.  Both the High Court and IPEC can grant injunctions and award damages.  Although the awarding of an injunction is discretionary, there is a high likelihood that a permanent injunction will be granted if the patentee is successful in proving its case. 

Although damages in the IPEC are capped at about 500,000 British pounds, there is no limit on damages in the High Court, however, awards are generally not as high as those typically seen in U.S. litigation.  While there is some discovery in the UK, it is nowhere near the level permitted in the U.S.  For example, there are no depositions in the UK.  However, courts have “disclosure”, a type of document discovery, which the courts require remain focused. 

Patent cases in the UK are heavily expert-driven.  Additionally, there is a bifurcated representation process. Barristers make arguments in court and solicitors collect information, draft briefs and interface with the client.  Moreover, the UK also has a “loser pay” system, where the winning side is able to recover a portion of its legal costs.  In the IPEC, recovery is limited to about 50,000 British pounds.  Although there is no cap for costs in the High Court, generally, the winning side recovers about 60-70 percent of its costs.

A party may appeal from either the Patents Court or the IPEC to the Court of Appeal. There is no automatic right of appeal and the losing party must seek permission to appeal from either the first instance court or the Court of Appeal. An appeal will typically be allowed on questions of law, rather than findings of fact or evidence-based issues.  After the Court of Appeal, a party may appeal to the Supreme Court. Permission is rarely granted and usually only on a point of law or for important public policy reasons.

Direct Infringement

Under section 60(1) of the Patents Act 1977 (Patents Act), a patent is infringed if any of the following acts are carried out in the UK:

  • Where the invention is a product, a person (or company) makes, disposes of, offers to dispose of, uses or imports the product or keeps it, whether for disposal or otherwise;
  • Where the invention is a process, a person (or company) uses the process or offers it for use in the United Kingdom when it is known, or it is obvious to a reasonable person in the circumstances, that its use there without the consent of the proprietor would be an infringement of the patent; or
  • Where the invention is a process, a person (or company) disposes of, offers to dispose of, uses or imports any product obtained directly by means of that process or keeps any such product, whether for disposal or otherwise.

However, in order to decide whether direct infringement is present, it is first necessary to construe whether an allegedly infringing product or process falls within the scope of the claims.  As in other European jurisdictions, patents must be construed in the UK in accordance with Article 69 of the European Patent Convention and the Protocol on the Interpretation of Article 69 of the EPC.

Claim construction

Article 69 European Patent Convention (EPC) describes the scope of protection provided by a patent and states: “The 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.”  Further guidance is provided in the Protocol to Article 69 (Protocol) of the EPC.  Article 1 of the Protocol requires that when determining the scope of protection of a patent, a balance be struck between the strict, literal meaning of the words of the claim and using the claims as merely a guideline.  Specifically, Article 1 states:

Article 1 – General principles

Article 69 should not be interpreted as meaning that the extent of the protection conferred by a European patent is to be understood as that defined by the strict, literal meaning of the wording used in the claims, the description and drawings being employed only for the purpose of resolving an ambiguity found in the claims. Nor should it be taken to mean that the claims serve only as a guideline and that the actual protection conferred may extend to what, from a consideration of the description and drawings by a person skilled in the art, the patent proprietor has contemplated. On the contrary, it is to be interpreted as defining a position between these extremes, which combines a fair protection for the patent proprietor with a reasonable degree of legal certainty for third parties.

Article 2 of the Protocol also makes it clear that equivalents must be considered when determining the scope of protection:

Article 2 – Equivalents

For the purpose of determining the extent of protection conferred by a European patent, due account shall be taken of any element which is equivalent to an element specified in the claims.

As will be discussed in more detail herein, the UK Supreme Court in Actavis v Eli Lilly ([2017] UKSC 48 (12 July 2017)), established a doctrine of equivalents consistent with Article 2 of the Protocol by introducing a new two-part test for determining infringement in the UK.  Specifically, the test asks the following questions:

  1. Does the variant infringe any of the claims as a matter of normal interpretation; or
  2. 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 question is “yes”, then infringement exists.

With respect to question 1, claims are construed according to their “normal interpretation”.  Specifically, a “purposive approach” (described in cases such as Catnic [1982] RPC 183, Improver [1990] FSR 181 and Kirin-Amgen [2005] RPC 9) is used.  Under the purposive approach, the scope of a claim is defined by giving effect to “what the skilled person in the art would have understood the patentee to be claiming”. This is an objective interpretation of the language of the claim, through the eyes of the skilled addressee (who brought with them their common general knowledge) in light of the description and drawings of the patent. 

If infringement is not established under a normal interpretation (question 1), a court will consider whether there is infringement under the doctrine of equivalents using question 2.  Question 2 requires determining whether a variant is “immaterial”.  Determining whether a variant is immaterial involves performing a three-part test which asks the questions:

  1. Notwithstanding that it is not within the literal meaning of the relevant claims 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 using the above three-part test, a patentee has to establish that the answer to the first two questions is ”yes“ and the answer to the third question is “no“.  In decisions subsequent to Actavis, such as, for example, Icescape v Ice-World ([2018] EWCA Civ 2219), the correct identification of the inventive concept appears to be the key when assessing a question of infringement under the doctrine of equivalents.  In fact, what the post-Actavis cases seem to suggest is that under the doctrine of equivalents what matters more is the core of the inventive concept that the claim seeks to protect and less the actual meaning of the words in a claim. 

Reliance on the Prosecution History (Prosecution History Estoppel)

Reliance on the prosecution file when considering whether a variant infringes a patent is only appopriate in certain or limited circumstances.  Specifically, consideration of the prosecution file is warranted (1) when the point at issue truly cannot be resolved by study of the claims or description, and the contents of the file unambiguously resolves the point,  or (2) where it would be contrary to the public interest for the contents of the file to be ignored.  An example of the latter would be where a patentee made it clear during prosecution that he did not regard a variant as falling within the scope of protection, but then subsequently asserted that that variant infringed the claim at issue. 

Supreme Court’s decision in Actavis v. Eli Lilly

Actavis involved Eli Lilly’s (Lilly) European Patent No. 1,303,508 (the ’508  patent).  The ’508 patent claims the use of the compound pemetrexed disodium in combination with vitamin B12 to inhibit tumor growth.  The combination reduces the known toxic effects of anti-folates, like pemetrexed disodium, in the treatment of cancer and has been marketed by Lilly under the brand name Alimta since 2004.  The relevant claims of the ’508  patent were claims 1 and 12.  However, the Court’s reasoning focused on claim 1 (in Swiss form) which recites:

  1. Use of pemetrexed disodium in the manufacture of a medicament for use in combination therapy for inhibiting tumour growth in mammals wherein said medicament is to be administered in combination with vitamin B12 or a pharmaceutical derivative thereof [which it then specifies].”

Actavis’s proposed generic products involved pemetrexed compounds used together with vitamin B12 for cancer treatment.  However, instead of pemetrexed disodium, the active ingredient in Actavis‘s products were (a) pemetrexed diacid, (b) pemetrexed ditromethamine, or (c) pemetrexed dipotassium. 

Lilly brought an infringement claim against Actavis in the High Court.  The High Court granted Actavis a declaration of non-infringement.  The Court of Appeal agreed that there was no direct infringement but concluded that Actavis’s products indirectly infringed the patent.  The Supreme Court concluded that Actavis directly infringed the patent and also dismissed Actavis’s cross-appeal on the basis that even if the products did not directly infringe, they would indirectly infringe as held by the Court of Appeal.

With respect to question 1, the Supreme Court found that Actavis‘ products did not infringe on the basis of a normal interpretation of claim 1.  However, with respect to question 2, the Court concluded that all of Actavis‘s products involved a medicament containing the pemetrexed anion and vitamin B12, and thus achieved substantially the same result in substantially the same way as the invention.  Once one knew Actavis‘s products achieved substantially the same result as the invention, the notional addressee of the patent would have thought it obvious that this was so, particularly as s/he would have regarded investigating whether pemetrexed free acid, pemetrexed ditromethamine or pemetrexed dipotassium worked as a routine exercise.  With respect to the third question, the Supreme Court felt that the Court of Appeal placed too much weight on the words of the claim.  The Supreme Court felt that it was very unlikely that the notional addressee would have concluded that the patentee could have intended to exclude any pemetrexed salts other than pemetrexed disodium from the scope of protection.  Therefore, the Supreme Court provisionally concluded that Actavis’s products directly infringed claim.

With respect to the prosecution history, the Examiner rejected the claims for use of the term ”anti-folate“ for reasons of disclosure and clarity under Articles 83 and 84 EPC.  In response, Lilly proposed amending the claims to the word ”pemetrexed“.  The Examiner objected on the basis of added matter under Article 123(2) stating that there was no basis for such terminology because pemetrexed was a distinct compound from pemetrexed disodium.  Lilly filed new claims reciting ”pemetrexed disodium“ and the application proceeded to grant.  The Supreme Court stated that the Examiner was wrong to take the view that the patentee should be limited to pemetrexed disodium because the teaching of the patent did not expressly extend to any other anti-folates.  Nonetheless, the Court stated that even if the Examiner was right or at least justified in taking the stance that he did, this did not have any bearing on the question of whether any pemetrexed salts other than pemetrexed disodium should be within the scope of the patent pursuant to the doctrine of equivalents.  According to the Court, ”The whole point of the doctrine is that it entitles a patentee to contend that the scope of protection afforded by the patent extends beyond the ambit of the claims as construed according to normal principles of interpretation.“  Thus, the Supreme Court felt that the contents of the prosecution file did not justify departing from the prelimary conclusion that the Actavis products directly infringed claim 1.

This post was written by Lisa Mueller of Casimir Jones, and Anne Marie Carr of Murgitroyd, UK/Ireland.          

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