Second medical use claims – construction of Swiss claims and indirect infringement

Warner-Lambert Company, LLC v Actavis Group PTC EHF & Others [2015] EWCA Civ 556 28 May 2015

Introduction

In our previous article on the Warner-Lambert case, we reported on Arnold J’s refusal to grant Warner-Lambert interim relief against Actavis in the above proceedings which concern second medical use claims in the “Swiss form” (i.e. “the use of compound X for the preparation of a medicament for treating indication Y”). The Court of Appeal has overruled Arnold J’s decision at first instance on the construction of Swiss form claims and therefore the approach to determining whether such claims are infringed.  The key points from the Court of Appeal’s decision are discussed below.

Factual background

Warner-Lambert is the proprietor of a patent claiming the use of pregabalin for the preparation of a medicament for treating neuropathic pain. Patent protection for pregabalin itself has expired and Actavis has launched its own pregabalin product, whose product information leaflet excludes the patented indication (a so-called “skinny label”). However, it is inevitable that a significant portion of Actavis’ pregabalin product will be used to treat the patented indication since (a) the market for the patented indication is significant, (b) doctors are encouraged to prescribe by generic name and (c) pharmacists are not made aware of the indication for which a drug is prescribed. Warner Lambert commenced infringement proceedings against Actavis and applied to court for interim relief (requiring Actavis to take certain steps to ensure that its product would not be used for the patented indication). It was in this context that the court was called on to decide whether Warner-Lambert’s direct and indirect infringement claims against Actavis had a real prospect of success at trial.

In the proceedings before Arnold J, the parties were agreed that the word “for” in a Swiss form claim meant “suitable for and intended for”. There was no dispute about the suitability of pregabalin for treating pain. Accordingly, the issue to be decided was the meaning of “intended for”. Arnold J held that “intended for” referred to the subjective intention on the part of the manufacturer that the medicament in question will be used to treat the patented indication.

Arnold J also struck out Warner-Lambert’s claims that Actavis was liable for indirect infringement. In the UK, indirect infringement requires, inter alia, the supply from one person to another of a means relating to an essential element of an invention for putting the invention into effect.  In Arnold J’s view, Swiss form claims cannot be indirectly infringed. Inventions in the form of Swiss claims are put into effect by means of a manufacturing process. However, no manufacturing process takes place by customers of Actavis or anyone else further downstream in the supply chain.

Construction of Swiss form claims

The Court of Appeal adopted the usual approach to claim construction, namely what would the skilled reader understand the language of the claim to mean. Both parties agreed that a Swiss form claim must involve some form of mental element. If the meaning of “for” was limited to “suitable for”, the claim would not be novel over the prior art. The Court of Appeal agreed with the parties that it was not correct to start off by determining the meaning of the word “intention” in the abstract, or by reference to other areas of the law, and import that meaning into the claim.

According to the Court of Appeal, it is necessary to determine the category of the claim and its technical features. Together, these elements comprise the technical subject matter of the claim. The Court of Appeal noted that Swiss form claims are process claims and that in this case the technical feature of the claim concerned the ultimate purpose of the product, namely the intentional treatment of pain. In view of this, the subject matter of the claim was considered to be “making pregabalin for patients to whom it will be intentionally administered for treating pain”.

The Court of Appeal went on to determine the meaning of the word “for” on this basis, the most realistic possibilities being (a) foreseeability that the drug will intentionally be used for the patented indication and (b) a subjective intention to that effect.

The Court of Appeal rejected Actavis’ submissions, and Arnold J’s finding, that the word “for” should be construed by reference to subjective intention. The Court of Appeal saw “real difficulties” with the application of such a test since it would require patentees to prove the subjective intention of a manufacturer and would rob Swiss claims of much of their enforceability. The Court of Appeal held that the skilled person would understand the patentee to use the word “for” in the claim to require that the manufacturer knows (whether that knowledge is actual or constructive) or could reasonably foresee that some of its drug will intentionally be used for pain.

Indirect infringement

The Court of Appeal agreed with Arnold J’s observation that indirect infringement of Swiss claims is difficult since there is no downstream event which, as a whole, can be regarded as putting the invention into effect.

However, the Court of Appeal held that it was arguable that the requirement to “put the invention into effect” in the context of indirect infringement may refer to the actions of two different people, for example, a combination of the manufacturer and user. It also noted that two EPC member states have held that Swiss form claims can be indirectly infringed in analogous circumstances. Accordingly, the Court of Appeal held that Warner-Lambert’s claims of indirect infringement should not be struck out and should be allowed to proceed to trial.

Comment

The Court of Appeal’s decision on the construction of Swiss form claims will no doubt be welcomed by patentees, particularly in view of the fact that the construction adopted by Arnold J would have significantly diminished the value of Swiss form claims in many cases. However, the decision does present generic companies with legitimate difficulties. In the circumstances of this case, patent protection for pregabalin itself has expired yet, due to the way in which drugs are prescribed and dispensed in the UK, Actavis could still be found to infringe notwithstanding that steps have been taken to reduce the likelihood of its product being dispensed for the patented indication.

Although the Court of Appeal considered a number of ‘hard cases’ that gave rise to unfair results, it did not allow these to influence its decision on the construction of Swiss form claims. Floyd LJ suggested that “any perceived unfairness may lie in the relief to be granted” and that if Actavis was found to infringe at trial “it does not follow that unqualified relief will be granted”.  However, if damages were to be payable by Actavis in respect of infringements, then in circumstances where Actavis can do little to avoid infringement (because of cross-label dispensing being a feature of the UK market beyond the control of generic manufacturers) and where Actavis’ profits on each sale are expected to be less than those of Warner-Lambert’s, an assessment on the usual basis may itself create unfairness and dissuade generic companies from entering the non-patent market.  This might suggest that an alternative basis for assessing damages such as reasonable royalty would be more appropriate, but this would significantly water down the value of second medical use patents.

The Court of Appeal’s construction of Swiss form claims appears to have blurred some of the distinction between direct and indirect infringement since the mental element required in both cases is now quite similar (i.e. constructive knowledge or foreseeability). This is perhaps not all that surprising once it is accepted that the infringement of Swiss form claims must involve some mental element which is in contrast to most other types of claim where direct infringement is a matter of strict liability and requires no mental element.  However, Arnold J’s construction requiring subjective intention did more to preserve the distinctions between these two types of liability.

Published with minor amendments in the IP Forum, Issue 102: September 2015