The Patent Review 2013/14: Infringement of Swiss Form Second Medical Use Claims: Need for Subjective Intention

15 April 2015

Neil Jenkins, Audrey Horton

Interim Injunction

Warner-Lambert LLC v Actavis Group PTC EHF and others [2015] EWHC 72 (Pat), Arnold J

Warner-Lambert marketed pregabalin, a prescription-only drug, for three different indications under a single registered trade mark, Lyrica. Patent protection for the drug itself had expired but Warner-Lambert owned a patent relating to the second medical use of pregabalin for pain relief (being one of the three indications for which the drug was marketed). Actavis had applied for a marketing authorisation for a generic version of pregablain limited to the other two indications.

Warner-Lambert was concerned that the generic drug would nevertheless be dispensed for the patented indication because most prescriptions are written generically and very few prescriptions state the indication for which the drug has been prescribed. Warner-Lambert also argued that because a generic version of a branded drug is usually cheaper than the branded product, pharmacists have a strong commercial incentive to dispense the generic version of the branded drug unless positive steps are taken to prevent this from occurring.

Warner-Lambert sued Actavis for patent infringement and at the same time sought an interim injunction requiring Actavis to take specific actions to prevent its generic version of the drug being dispensed to patients who had been prescribed the drug for the patented indication. It was common ground that although the injunction being sought was mandatory rather than prohibitive in nature the test to be applied was the same namely the principles laid down in American Cyanamid v Ethicon [1975] AC 396.

The first issue to be determined by the Court therefore was whether there was a serious issue to be tried. 

The second medical use claims in the patent were in the "Swiss form" i.e., “use of substance X for the preparation of a medicament (or pharmaceutical composition) for treating indication Y”. Swiss form claims are regarded as purpose-limited process claims. Warner-Lambert’s primary claim for infringement therefore was under section 60(1) (c) of the Patents Act 1977 namely, the offer for sale and sale of a generic drug being a product obtained directly by means of the process the subject of the claim. There was no dispute that if Actavis carried out the process of the claims then their generic product would be a product obtained directly by means of the patented process.

The dispute centred on whether the manufacture of pregabalin would fall within the scope of the claims and that dispute in turn centred on the meaning of the words "for treating … pain." It was common ground that the word "for" in a Swiss form claim meant "suitable and intended for". It was also common ground that the generic product obtained by the use of pregabalin for the preparation of a pharmaceutical composition was suitable for treating pain. The issue to be decided by the Judge was whether the generic product obtained by the use of pregabalin for the preparation of a pharmaceutical composition was intended for treating pain. To answer that question, the Judge had to answer two other questions: "whose intention was relevant and what was meant by intended?"

As regards the first question, the Judge held that the relevant intention was that of the manufacturer (not as Warner Lambert contended the intention of the person who disposes of the generic product).

As regards the second question, the Judge held that intended in this context meant subjective intention on the part of the manufacturer that the drug should be used for the patented indication (not as Warner-Lambert contended that it was sufficient if it was foreseeable that it would be likely to dispensed for treating the patented indication).

The court noted that cases from other EU jurisdictions supported the proposition that subjective intent was required and it held that the word "for" in Swiss form claims imported a requirement of subjective intention on the part of the manufacturer that the medicament or pharmaceutical composition would be used for treating the specified condition.

The Judge refused to grant the interim injunction. There was no serious issue to be tried as Actavis would not infringe the patent by marketing the drug for the permitted indications. As the relevant claim was to a process of manufacture, infringement would require a subjective intention by Actavis, as the manufacturer, that the drug would be used for treating the patented indication. While Actavis might foresee that the product might be prescribed for the patented use, it did not have the requisite intention.

As Warner-Lambert had not relied on any allegation of subjective intention on the part of Actavis in support of its application for an interim injunction, the Judge therefore concluded that there was no serious issue to be tried and dismissed the application.

NB. At the hearing, Warner-Lambert indicated an intention to apply to amend its claim so as to plead a case of subjective intention which application was permitted at a subsequent hearing.

On 10 February 2015, the Court of Appeal granted Warner-Lambert permission to appeal against Arnold J's refusal to order an interim injunction. That appeal has been fixed to be heard at the end of April 2015.