Novartis AG v Dexcel-Pharma Ltd

A previous construction of a patent claim binds a later court only as to the precise legal point decided. Where that conclusion materially depended on evidence which was absent or different, the later court may reconsider the issue. On an application for an interim injunction, the claimant must show a serious issue to be tried and provide sufficiently precise evidence that it has a real prospect of obtaining a final injunction. The court should avoid a mini-trial, then assess the balance of convenience and, where appropriate, preserve the status quo.

Novartis, proprietor of a patent for cyclosporin pharmaceutical compositions, sought an interim injunction preventing Dexcel from marketing DEXIMUNE. Dexcel argued that earlier construction and infringement decisions concerning the same patent meant there was no serious issue to be tried. The dispute concerned whether DEXIMUNE contained the claimed hydrophilic and lipophilic phases and formed the required micro-emulsion, including whether the relevant phases had to exist in the pre-concentrate or only after dispersion in water.

The court also considered the evidential and legal effect of the earlier decisions, the competing commercial risks, and the preservation of the status quo pending trial.

1. Previous construction. A subsequent court is bound by an earlier decision on a question of law, but must identify the precise legal point decided. Patent construction is not necessarily a pure question of law because common general knowledge, the disclosure conveyed to the skilled person, and factual evidence about the consequences of the specification may materially affect the conclusion. It was seriously arguable that a later court was not bound where the earlier conclusion depended materially on evidence that was absent or materially different.
2. Serious issue to be tried. The court should not conduct a mini-trial on expert statements without cross-examination. The party seeking relief must nevertheless provide sufficiently precise evidence to establish a real prospect of obtaining a permanent injunction at trial. In a patent case, that evidence must enable the court to form a view that each claim feature may be present in the alleged infringement.
3. There was a serious issue as to infringement. DEXIMUNE contained a proposed lipophilic component capable, on Novartis’s evidence, of carrying cyclosporin and forming the oil phase. This materially distinguished the case from the earlier formulation involving a surfactant incapable of performing that function. The question whether phases had to exist in the pre-concentrate, rather than in the resulting aqueous micro-emulsion, had not clearly been concluded by the earlier judgment.
4. Balance of convenience. The court then assessed the balance of injustice, taking account of the likely losses to both parties, the remaining life of the patent, the risk of market disruption and the parties’ conduct. Dexcel had known of the patent risk and had the opportunity to clear the position before launch but had not done so. The balance favoured Novartis. Even if the balance had been even, preserving the status quo, namely no allegedly infringing product on the market, was appropriate.
5. The interim injunction was granted. The court did not resolve the disputed technical evidence or determine the ultimate construction and infringement issues.