Actavis v Eli Lilly & Co. [2014] EWHC 1511 – Arnold J granted a Declaration of Non-Infringement in relation to the UK, French, Italian and Spanish designations of Eli Lilly’s EP.

The case of Actavis v Eli Lilly & Co. (Actavis UK Limited and others v Eli Lilly & Company [2014] EWHC 1511 (Pat)) has been watched with interest since 2012 when Arnold J held the English Court did have jurisdiction to hear a claim concerning non-UK designations of a European Patent (EP). On 15 May 2014, Arnold J gave judgment on the merits of the action and granted a Declaration of Non-Infringement (DNI) to Actavis for its planned generic pemetrexed product in relation to the UK, French, Italian and Spanish designations of Eli Lilly’s EP.

The DNI action related to the cancer treatment pemetrexed. Eli Lilly (Lilly) markets pemetrexed disodium under the brand name ALIMTA. Lilly’s compound protection for ALIMTA expired on 10 December 2010 but it has a secondary patent (EP 1 313 508) covering the use of pemetrexed disodium in combination with vitamin B12 or a pharmaceutically acceptable derivative thereof and optionally a folic protein binding agent. The invention of the patent was that by combining pemetrexed with these other agents toxic side effects could be reduced.

Actavis sought DNIs for its generic pemetrexed product which was expected to be one of three candidate products it had in development: pemetrexed diacid (the lead candidate), pemetrexed dipotassium or pemetrexed ditromethamine. ALIMTA would be used as the reference medicine when seeking regulatory approval. The Court had to determine whether Actavis’s three candidates were within the scope of the claims of the patent by applying Article 69 of the EPC and the Protocol and by considering the doctrine equivalents where that was to be applied under national law. In addition to the substantive question of infringement, there was also an argument about the correct law to apply when assessing whether a DNI could be issued.

Lilly counterclaimed for infringement only of the UK designation.

Applicable law

Each claim had two elements – the ability of the claimant to seek a DNI (e.g. taking into account locus standi or procedural considerations) and the substantive assessment of infringement.

There was no dispute that the law to be applied when assessing infringement was the national law for each designation of the patent (in accordance with Article 8(1) of the Rome II Regulation) e.g. infringement of the Spanish designation would be assessed under Spanish law. Therefore Arnold J heard evidence as to the national law in France, Italy and Spain.

Initially both parties had accepted that the law to be applied when assessing the Court’s power to grant a DNI would be the lex fori i.e. English law, on the basis that this was a question of procedure or remedy and therefore outside the scope of the Rome II Regulation (as stated in Article 1(3)). However by the time of trial, Lilly asserted that the right for Actavis to obtain a DNI should also be assessed under each national law rather than under English law. This would entail a more complex set of procedural requirements which Actavis would have to show it had met for each designation.

Arnold J held that the conditions that would have to be satisfied in order to be eligible for DNI relief were procedural and that the DNI action did not fall into any of the other categories set out in the Rome II Regulation. Therefore it was correct to apply English law when considering the availability of the declaration. Nevertheless, Arnold J went on to analyse the position on the assumption that national laws did apply, and similarly found that Actavis had satisfied all the necessary conditions.

Claim construction and prosecution history

When assessing infringement, the judge had to determine whether any of Actavis’s pemetrexed products fell within the scope of Lilly’s claim to “pemetrexed disodium”. Actavis argued that the skilled team would understand that pemetrexed disodium included only that and nothing else, whereas Lilly argued that it meant (at least) pemetrexed diacid and any pharmaceutically acceptable and sufficiently soluble salt of pemetrexed. Lilly’s justification for this construction was that it would be obvious to the skilled team that substitution of the free acid or a different salt would have no material effect on the way in which the invention worked.

Arnold J decided to use the “Improver questions” as a framework to consider whether pemetrexed diacid was within the scope of the claims, as this would also assist with comparing the situation under French, Spanish and Italian law. Applying all of the national laws the Court found that Actavis’s proposed pemetrexed products would not infringe.

One particularly interesting aspect of the case was the judge’s consideration of the prosecution history of the patent. Arnold J reviewed the English law on examining the prosecution history and held that, although there was no doctrine of “file wrapper estoppel” in the UK (as, for example, in the US), prosecution history is admissible as an aid to construction. Lilly had initially applied for a claim including an “antifolate”, then to “pemetrexed” and finally to “pemetrexed disodium” to avoid the objections of the EPO. In the Court’s view, Lilly’s reliance on the doctrine of equivalents showed that it regretted the decision it had taken during prosecution and was trying to avoid the consequences. In that scenario, there was no reason why the law should be sympathetic to the patentee.

The case is also of note because of the contradictory decisions of two European Courts; the

Düsseldorf Court gave a finding of infringement of the German designation of the patent in April 2014, shortly before the English Court awarded a DNI. When explaining why the English Court reached a different decision to the German Court, Arnold J attributed the difference to a difference in evidence before the two courts (in particular the cross-examination which took place before the English Court), a difference in the exact arguments run and a different assessment of the identity of the skilled addressee. However he also said that in his view the German Court had not given proper effect to the Article 69 Protocol.