The Actavis v Eli Lilly UK litigation concerning pemetrexed (sold by Eli Lilly under the brand Alimta®) relates to Actavis’ innovative application to the English court for declarations of non-infringement (DNIs) of national designations of a European Patent in addition to the UK designation. On 25 June 2015, the Court of Appeal refused to grant the declarations sought by Actavis. This overturned the decision of Mr Justice Arnold in the Patents Court, who had held that each of the UK, French, Italian and Spanish national designations of Eli Lilly’s European patent were not infringed by the pharmaceutical products that Actavis intended to sell in each of those countries. The Court of Appeal agreed with the trial judge’s conclusion that the patents were not directly infringed but overturned his decision on contributory infringement. The Court of Appeal’s judgment raises several points of wider interest, in particular in relation to claim construction, second medical use patent claims and the procedural requirements to seek DNIs of foreign patents before the English court.

Claim construction

At first instance, the Patents Court had relied on the prosecution history as a guide to construction of the patent claim. During prosecution, the patentee had amended the wording of the claims sought. The Court of Appeal strongly disagreed that the prosecution history was useful and should be used in this manner on this occasion. Indeed, the judgment from the Court of Appeal suggests that if either party had contended that the prosecution history was inadmissible as a matter of law it is likely that the Court would have agreed. In so finding, the Court noted that the person skilled in the art does not always read the prosecution history, particularly as it is often of limited value. In this case, the Court of Appeal therefore declined to consider the prosecution history, albeit that the Court came to the same conclusion on scope of protection as the trial judge had.

The Court also considered the application of the Improver or Protocol questions in construing the patent claims. The questions have fallen out of favour in the UK following the seminal decision of the House of Lords on claim construction in the Kirin Amgen case in 2005, but were applied by the judge at first instance in this case. As Actavis were also seeking declarations under certain foreign patent laws where the questions, or variations of them, are used more frequently it is possible that the judge was persuaded to do so as a one-off, and this is not the beginning of a novel trend towards their reintroduction. Nevertheless, the Court of Appeal endorsed their application on this occasion.

Second medical use claims

The relevant second medical use claims of the patent in suit were in both Swiss-type and EPC 2000 form. In reaching its decision on indirect infringement, the Court made a number of interesting findings. In particular, the Court was of the view that as second medical use claims must involve the step of manufacturing a medicament for treating a disease, a formulation chemist would generally have to be part of the team that forms the person skilled in the art. Moreover, the Court held that a second medical use claim includes a requirement that the manufactured medicament is to some extent effective for treating the disease.

Further, the Court held that, in this case, the dissolved lyophilisate (Actavis’ proposed product was a lyophilisate intended for reconstitution by the doctor) could be the medicament referred to in a second medical use claim, and the manufacture of that medicament could take place by the physician rather than just the manufacturer of the medicinal product placed on the market. That is likely to open up more manufacturers of generic pharmaceutical products to liability for contributory infringement of second medical use claims where the requisite knowledge can be demonstrated.

As Actavis had conceded that it intended for its products to be dissolved in saline, which would inevitably lead to formation of some of the pemetrexed salt claimed in the patent, the Court held that it would infringe the UK patent. As it was common ground between the parties that there was no detectable difference in the laws of France, Italy and Spain regarding the approach to contributory infringement, the court therefore held that Actavis’ products would also infringe the three non-UK patents in suit and thus refused to make any of the declarations sought.

Declarations of non-infringement of foreign patents

Whilst the Court of Appeal refused to grant the declarations sought on the basis that Actavis’ products infringed the patents in suit under contributory infringement, the Court gave an obiter ruling on which country’s procedural requirements an applicant must satisfy before commencing an action before the English courts to obtain a DNI. It was noted by the Court that English law took the most relaxed attitude amongst the four states in question of what a party must show before it can apply to the court for a DNI, and that Actavis had satisfied that requirement under the lex fori, i.e. English law. However, Eli Lilly had argued that an applicant should be required to satisfy the law of the national designation of the European patent, the lex causae.

In the Court’s view, the rules at issue were conditions of admissibility of rights rather than rules concerning the substance or content of the parties’ rights. Or in other words: “They are all concerned with whether the court should hear a dispute about substance. They are not concerned directly with the substance itself”. Such rules would traditionally be considered, for private international law purposes, as procedural and not substantive and thus subject to the lex fori and not the lex causae. Therefore, only if the exceptions in the Rome II Regulation applied should the Court not apply the lex fori. According to the Court, none of the exceptions in the Regulations encompassed the rules for admissibility of a DNI. Therefore, had Actavis been entitled to the DNIs as a matter of patent construction/infringement, the Court would have granted them.

Prior to handing down judgment, Actavis also requested that the case be remitted for further trial in the Patents Court in relation to a proposed new product for reconstitution with dextrose rather than saline. In July 2015 it was ordered that this trial in the Patents Court take place in early November 2015. There will therefore be more to come from this dispute.