Home > Insights > Warner-Lambert v Actavis – further guidance on infringement of second medical use claims
12 October, 2015

In the full trial of Warner-Lambert v Actavis, Mr Justice Arnold has ruled that Warner Lambert’s patent directed to pregabalin for treating pain is invalid, but in any event, is not infringed by the manufacture and supply by Actavis of its generic product (Lecaent). Importantly, the judgment provides guidance as to how infringement of Swiss-type second medical use claims should be assessed.

To recap, Warner-Lambert markets pregabalin under the trade name Lyrica for the treatment of epilepsy, generalised anxiety disorder (GAD) and neuropathic pain. Basic patent protection for pregabalin has expired leaving Warner-Lambert’s patent, EP(UK) 0 934 061 (the Patent), as the only barrier to generic companies. Generics UK Ltd. (trading as Mylan) and Actavis challenged the validity of the Patent in 2014. Then, after learning of Actavis’ intended launch of Lecaent, Warner-Lambert counterclaimed for infringement of the Patent. Actavis subsequently launched Lecaent in February with a “skinny label” limited to the non-patented indications of epilepsy and GAD.

This judgment by Arnold J is the decision in the combined revocation and infringement actions. It follows several interim judgments by Arnold J including, in January, his refusal to award interim relief against Actavis (see our bulletin) and, in March, his subsequent order to NHS England to issue guidance regarding the prescription of pregabalin (see April Newsletter). In June, the Court of Appeal upheld Arnold J’s judgment refusing to award interim relief but ruled that Warner-Lambert did have an arguable infringement case and in so doing, provided guidance on construction of Swiss-type second medical use claims.

Arnold J held the Patent to be invalid based on a lack of sufficiency. A key consideration in the reasoning was the fact that the claims cover central neuropathic pain. Whilst pregabalin has subsequently been authorised for this indication (as well as others), it is established law that post-published evidence cannot remedy a lack of sufficiency at the filing date. Instead, the disclosure of the Patent specification must make it plausible that the invention will work across the scope of the claims. In reaching his conclusion, Arnold J made it clear that this test is not satisfied by demonstrating that the Patent specification provides sufficient data to make the claimed subject matter “obvious to try”. Instead it must make it possible for the skilled person to make a “reasonable prediction” that the claimed subject matter will work.

Notwithstanding his conclusion that the Patent was invalid, Arnold J considered the direct and indirect infringement claims. With regard to direct infringement, Arnold J referred to the Court of Appeal’s judgment of June this year in relation to the construction of Swiss-type claims in which Floyd LJ dismissed a requirement for subjective intent stating that:

“I can therefore see no reason why the skilled person would conclude that the word ‘for’ implied subjective intent…In my judgment, therefore, the skilled person would understand that the patentee was using the word ‘for’ in the claim to require that the manufacturer knows (in the above sense) or can reasonably foresee the ultimate intentional use for pain, not that he have that specific intention or desire himself.”

In reluctantly following this interpretation, Arnold J explained that since Swiss-type claims are process claims directed at the manufacturer, the relevant date on which the manufacturer’s knowledge (or mental state) is to be assessed is the date of manufacture. In addition, after considering whether doctors, pharmacists or even patients could provide the required intentional use, he concluded that it could only be provided by a pharmacist who knows that the doctor has prescribed generic pregabalin for treating pain and dispenses Lecaent.

The question considered by Arnold J was therefore whether it was foreseeable to Actavis that, in cases where the prescription indicated that generic pregabalin had been prescribed for pain (only 5%), the pharmacist would dispense Lecaent despite the fact that it was not licensed for pain. Arnold J concluded that the answer to this question was “no” save for a small number of exceptional cases, which he considered it proper to regard as de minimis. One of the main justifications for this conclusion was Actavis’ decision to notify superintendent pharmacists before launch of Lecaent that it was not licensed for the treatment of pain. Therefore, Actavis’ activities did not amount to direct infringement of the Patent.

With regard to the indirect infringement claim, despite the Court of Appeal in June having overturned his first instance interim judgment that struck out Warner-Lambert’s indirect
infringement arguments, this claim was once again swiftly dismissed by Arnold J. In his judgment, the fundamental difficulty is that the Swiss-type claims of the Patent are process claims (in contrast to EPC 2000 claims) and that:

“…there is no act of manufacture by any party downstream from Actavis…In particular, there is no act of manufacture by pharmacists… It follows that, although there is no difficulty in concluding that Lecaent’s active ingredient is “means, relating to an essential element of the invention, for putting the invention into effect”, Lecaent is not suitable for putting, or intended to put, the invention into effect: either the invention has already been put into effect by the time that Lecaent leaves Actavis’ hands or it is not put into effect at all.”

Of course, this reasoning leaves open the question as to whether the situation would be any different for an EPC 2000 claim being a purpose-limited product claim. Indeed, the difference in scope between Swiss-type claims and EPC 2000 claims was once again noted by Arnold J.

This and many other issues will no doubt be explored by the Court of Appeal assuming, as seems likely, Arnold J’s judgment is appealed.