There has been a series of important cases in European jurisdictions over the past year, in which the courts have addressed pharmaceutical second medical use patents – patents that claim a pharmaceutical for a particular therapeutic application – when there are other, non-patented indications for the drug in force, but the patent protection for the drug per se has expired.

In the latest development in this area the Court of Appeal of England & Wales has delivered judgment in the Warner-Lambert series of cases. In this case, Warner-Lambert claimed that Actavis would infringe its second medical use patent (drafted in a 'Swiss-claim' form) – for the use of pregabalin in the treatment of pain, and in particular neuropathic pain – by marketing Lecaent under a skinny label that excludes those indications. The case concerns the validity of the patent and both direct infringement and indirect infringement.

The patent has now been held partially invalid by the Court of Appeal on the basis that the relevant claim is insufficient because its scope covers neuropathic pain conditions that were not made plausible by the patent. The decision upholds the High Court decision.

This finding of invalidity against the relevant claims means that the patent could not be infringed (infringement of the surviving claims had not been asserted against Actavis). Nonetheless, the Court of Appeal went on to make obiter (non-binding) observations on the correct approach that should be taken to the direct and indirect infringement of second medical use Swiss-claims:

  • As regards direct infringement, it was held at first instance by Arnold J that there was no direct infringement. The Court of Appeal held that the test was an objective one – does the manufacturer know or is it reasonably foreseeable that pregabalin will intentionally be used to treat pain. The Court of Appeal held here that this knowledge or foreseeability can be "negatived" if the manufacturer has taken all reasonable steps in his power to prevent the use for the patented indication. This is the question that the judge should then have turned his mind to on the facts, but the Court of Appeal does not consider.
  • As regards indirect infringement, it was held at first instance that because Swiss-claims are process claims to the manufacture of a drug, the ultimate users – in this case pharmacists – are not using the drug to manufacture a pharmaceutical composition according to the claim and therefore supply cannot result in infringement. The Court of Appeal has disagreed with this reasoning, stating its view that the process of preparing the composition by a manufacturer can continue through any packaging step performed by the manufacturer and includes the labelling step performed by the pharmacist.

The decision