In 2017, the Pemetrexed or Actavis versus Eli Lilly case had a major impact on the case law on infringement under the doctrine of equivalency in many European jurisdictions. The case concerned a European patent claiming the use of the active ingredient pemetrexed disodium in combination with vitamin B12 to inhibit tumor growth. The infringing form comprised a different pemetrexed salt, pemetrexed dipotassium, the question being whether this fell within the scope of the patent. The description disclosed antifolates as an intrinsically suitable class of salts, although during the grant procedure pemetrexed disodium had been selected from the pemetrexed salts.
In contrast to the Federal Court of Justice’s (Bundesgerichtshof, BGH) Okklusionsvorrichtung case, in which the BGH had assumed a limitation of the scope of protection when making a selection decision between disclosed alternatives, the infringing form pemetrexed dipotassium was not disclosed in the description. However, the BGH did not extend its ruling regarding the selection between disclosed alternatives to non-disclosed-but-detectable alternatives. As a further aspect, the BGH referred to the history of the claim, wherein the applicant had to limit the patent claim in the grant procedure to the use of pemetrexed disodium as the only disclosed inventive subject matter. However, the BGH does not consider such a limitation to be a restriction of the equivalence range. In doing so, the BGH relativized the previously strongly emphasized case law on waiver, which was developed in the BGH rulings in the Okklusionsvorrichtung and Diglycid cases. In exceptional cases, the grant history can now be consulted in case of ambiguity, although this is to be handled restrictively.
In the UK, the impact of the Pemetrexed case was even more dramatic. Until then, there was basically no such thing as infringement under the doctrine of equivalency; rather, claims were interpreted according to the scope of protection sought by the patent proprietor from the perspective of the person skilled in the art. This view was reflected in the so-called three “Improver questions”. However, in the Pemetrexed case, the UK Supreme Court changed this doctrine by reformulating the first two Improver questions, taking into account the result achieved by the equivalent and the general inventive concept. This change led to a paradigm shift towards a case law that affirms equivalent patent infringement.
In Switzerland, a mixture of the first two questions in the Schneidmesser case and the third question in the Improver case has been established. The grant history is only taken into account when there is a waiver of the distinction from the prior art. In 2023, the Swiss Federal Supreme Court ruled in the Deferasirox case that in the context of infringement under the doctrine of equivalency, the ranges stated in the claim could not be extended, and tolerance ranges as in the case of literal infringement are not taken into account. Thus, case law in Switzerland is stricter than in Germany with regard to numerical ranges.
Austria has a long history with regard to infringement under the doctrine of equivalency and, since the Supreme Court decision in Bicalutamid II (2008), it has relied heavily on the BGH’s Schneidmesser questions. With regard to the question of detectability in the context of the second Schneidmesser question, inventive step plays a role – as it does in Germany. Number ranges are treated in Austria like other equivalent means, which means a less strict interpretation than in Germany and allows extending the scope of equivalence to number ranges as well. However, there is as yet no case law on implicit waiver through selection decisions.
In France, a two-step process has been established for determining infringement under the doctrine of equivalency. The first step is to determine whether the infringing form embodies all essential features of the claim. Essential features include those that are necessary to solve the technical problem, as well as features that have been included in the claim to establish novelty and/or inventive step. If this question is answered in the negative, examination is made as to whether the infringing form fulfils the same function of the non-realized essential feature with a similar result. However, this function must be new. Unlike in Germany, inventive step does not play a role in this examination, which tends to lead to a broader scope of protection. In the Technogenia v. Atelier Joseph case (confirmed in 2004 and 2007), the previously strict approach with regard to numerical ranges was relaxed so that these ranges are also subject to an equivalent examination. The grant history plays a role above all in the case of restrictions on the delimitation of novelty and inventive step.
In Italy, the Netherlands and Belgium, the Pemetrexed case led to a departure from the previously applied FWR (function-way-result) test. In this test, detectability did not play a role, but the grant history was taken into account. In Italy, the obviousness test replaced the FWR test and corresponds to a combination of the first two Schneidmesser questions. The Court of Cassation ruled in 2977/2020 (confirmed by 112/2022) that the previous practice of considering the grant history will be greatly limited.
In the Netherlands and Belgium, the Pemetrexed case led to the introduction of a mixture of Improver and Schneidmesser questions. The grant history continues to be taken into account, in particular the reasons for restrictions.
In summary, it can be said that the Pemetrexed case has started a trend towards harmonization of European case law on equivalent infringement. It is becoming apparent that existing systems such as the FWR test based on the US system and the classic Improver questions are being replaced by a list of questions based on continental case law. This leads to an objective interpretation of the claim, taking into account detectability and only a very limited consideration of the grant history. However, European case law remains fragmented with regard to the question of how numerical ranges are to be assessed in the context of an infringement under the doctrine of equivalency.