Warner-Lambert Company LLC v Generics (UK) Ltd t/a Mylan and anr [2018] UKSC 56
The Supreme Court has given its long-awaited decision on sufficiency and infringement of second medical use claims (in Swiss-form) and the approach to post-trial amendment of patents.
Following numerous decisions of the Patents Court and Court of Appeal, the position was:
- Claims 1 and 3 of Warner-Lambert’s patent, which covered the use of pregabalin to treat pain and neuropathic pain respectively, were invalid for insufficiency. Subsidiary claims limited to the treatment of peripheral neuropathic pain were valid as there was just enough in the patent specification to render such claims plausible;
- Even if claims 1 and 3 had been valid, Arnold J had held that Actavis would not have infringed because it did not have the requisite intention that its skinny label product would be used for the treatment of pain.
- On infringement, the Court of Appeal had expressed disagreement with Arnold J’s subjective intention test, preferring instead a test of foreseeability coupled with an assessment of whether all reasonable steps had been taken to prevent use for the patented indication;
- Warner-Lambert’s post-trial application to amend claim 3 so that it only covered peripheral neuropathic pain constituted an abuse of process.
On Warner-Lambert’s appeal and Mylan / Actavis’ cross-appeals, the Supreme Court held that:
1) On its correct construction, claim 3 covered both peripheral and central neuropathic pain;
2) Warner-Lambert’s post-trial amendment did constitute an abuse of process and the Judge had been right to dismiss it;
3) The teaching that pregabalin could be used to treat neuropathic pain of either kind (peripheral or central) was not plausible. Therefore, all those claims that covered the use of pregabalin to treat neuropathic pain were invalid for insufficiency;
4) Obiter if claims 1 and 3 had been valid, they would not have been infringed. There was a difference of views as to why: Lords Sumption and Reed concluded that intention was irrelevant and that the sole criterion was the presentation of the product as it emerged from the manufacturing process (“objective appearance” test). Lord Mance agreed that the objective appearance of the product was key but left open the possibility that in rare cases additional factors might come into play. Lords Hodge and Briggs favoured Arnold J’s test of subjective intention.
Kathryn Pickard appeared on behalf of Mylan and Actavis
Michael Silverleaf QC appeared on behalf of the NHS as intervener