The Court of Appeal have overturned the Patents Court's view on the issue of infringement of Warner-Lambert's Swiss-type second medical use patent for pregabalin.

The Court of Appeal decided there was an arguable case of infringement, ruling that it merely needs to be foreseeable that a pharmaceutical could be used for the indication claimed in the second medical use patent.

This lowers the bar from the 'subjective intention' test in the Patents Court ruling and brings the UK courts more into line with those in the Netherlands and Germany.

Swiss-type claims

A Swiss-type claim takes the form "use of drug X in the manufacture of a medicament in the treatment of disease Y". Swiss claims avoid the exclusion from patentability of methods of treating the human body, as they are directed at pharmaceutical manufacturers and not doctors.

Pregabalin and its marketed indications

Pregabalin is the active ingredient of the Warner-Lambert (part of Pfizer) product Lyrica®. The drug is approved in the European Union (EU) for three medical indications: treatment of epilepsy and generalised anxiety disorder (GAD), both disclosed and claimed in the basic patent covering the active ingredient, and neuropathic pain, which is the subject of a later use patent having Swiss-type claims.

Following expiry of the basic patent and regulatory data exclusivity periods, Actavis and other generic manufacturers prepared to launch a generic version of pregabalin, Actavis' product was sold under the name Lecaent. The generic products were sold with a label only mentioning the epilepsy and GAD indications, and not mentioning the patented treatment of pain. This is known as 'skinny labelling' and is specifically permitted by the EU medicinal products Directive (2001/83/EC). Actavis also launched revocation proceedings against the neuropathic pain use patent.

On notification of Actavis's plan to market Lecaent, Warner-Lambert counter-claimed for infringement – their concern being that physicians and pharmacists might prescribe and dispense the cheaper generic product for all indications, including off-label prescribing for the patented use of treating neuropathic pain. In advance of full trial concerning the validity of the use patent, Warner-Lambert applied to the court for an interim injunction requiring Actavis to take a series of steps to ensure its generic pregabalin product would not be dispensed for neuropathic pain.

First instance interim judgments in the UK, Netherlands and Germany

In the first instance case before the Patents Court in January, Mr Justice Arnold decided that there was no serious issue to be tried and therefore refused to grant an interim injunction.

Regarding direct infringement of claim 1 under section 60(1)(c) of the UK Patents Act which relates to infringement of a direct product of a process (this section applying as Swiss claims relate to a process of manufacture and not a product, the manufacturer being Actavis and not anyone else further downstream), the word "for" in Swiss-style claims was held to require an element of subjective intention on the part of the manufacturer that the medicament will be used for treating the specified condition (neuropathic pain). While Actavis could foresee that the product might be prescribed for the patented use, Warner-Lambert failed to demonstrate Actavis had the required intention.

Warner-Lambert had also initially pleaded indirect infringement under section 60(2) relating to supplying an essential means to put the invention into effect, but they did not press this point before the Patents Court. Following the initial decision, Actavis pleaded in a separate hearing for this point to be struck out completely. However, prior to the Court of Appeal hearing the Dutch and German courts both ruled in the patentee's favour on the issue of indirect infringement regarding similar 'skinny label' claims.

Interim appeal rulings

The Court of Appeal upheld the decision to refuse the interim injunction but took a different view on whether Warner-Lambert has an arguable case on direct infringement.

The Court of Appeal interpreted the claim that the skilled person would understand that the word "for" in the Swiss claim extended beyond simply making pregabalin, yet fall short of including the step of actually using pregabalin for treating pain (which would be an excluded method of treatment).

However, the Court of Appeal overturned the Patents Court's interim view that subjective intention was required on the part of the manufacturer to directly infringe the Swiss claim, and considered there to be an arguable case of direct infringement not only under section 60(1)(c), but also under section 60(1)(b).

The Court of Appeal ruled that the skilled person would understand that, if the manufacturer knows or could reasonably foresee that some of the drug will intentionally be used for pain, the manufacturer is making use of the patentee's inventive contribution.

Therefore, the Court of Appeal considered it unnecessary for the purposes of direct infringement that the manufacturer has that specific intention.

The court did acknowledge that this test of reasonable foreseeability raises some difficult questions. For example, a manufacturer selling a medicine before the priority date sees an increase in sales in relation to the new use that the manufacturer does nothing to solicit or even actively discourages – is it right that the manufacturer is made an infringer on the basis that the increase in sales was foreseeable?

The court must also balance the rights of the patentee to enforce the second medical use patent with those of the generic manufacturer to lawfully market the product for the off-patent uses. The court proposes that the answer to these issues of potential unfairness lie in the relief that may be granted on a finding of infringement.

The Appeal Court also considered there to be an arguable case of indirect infringement. The court gave weight to the Dutch and German decisions which considered that indirect infringement could occur in the circumstances of the case.

Based on their finding of threatened or actual infringement of the process claim under section 60(1)(b), the court also found that dealings downstream in the direct product of the process could also be infringements under section 60(1)(c).

Regarding indirect infringement under section 60(2), significantly the Court of Appeal found that the person supplying the means to put the invention into effect (with the requisite knowledge that it could be used for the stated indication) and the person who intentionally uses it for that indication need not be the same person. Therefore, the Court of Appeal ruled that there was an arguable case that the Swiss claim could be indirectly infringed if pregabalin is manufactured by one person with that knowledge and supplied to another who intentionally uses it for the treatment of pain.

For these reasons, the Court of Appeal allowed Warner-Lambert's appeal against the striking out of the indirect infringement aspect of their claim and allowed this point to proceed to full trial.

In the first instance proceedings, all parties agreed that the best solution to the problem, at least for interim purposes, was for the National Health Service (NHS) to give guidance regarding prescription.

The Patents Court issued an interim order to the NHS to prescribe pregabalin by the brand name Lyrica® for pain, but by its generic name for the non-patented indications of epilepsy and GAD. This guidance was subsequently issued by the NHS.

Warner-Lambert made further arguments before the Court of Appeal to attempt to overturn this (based on fears that the guidance may be ineffective or not be followed), but the Court of Appeal refused to interfere with the Patents Court's findings of fact and dismissed their appeal on this point.

What happens next?

The full trial was held at the Patents Court at the end of June 2015.

Both issues will probably be appealed, so the Court of Appeal will likely consider this matter once again.

In view of the fundamental issues this case raises regarding interpretation and infringement of second medical use claims, the matter may be further appealed to the Supreme Court.