Neurim Again! Final Injunctions - To Stay Or Not To Stay, That Was The Question

• Published date: 11 April 2022
• Subject Matter: Intellectual Property, Patent
• Law Firm: Marks & Clerk
• Author: Mr Ian Turner and Marcus Riby-Smith

In a recent decision the Court of Appeal has ordered a final injunction stayed pending the outcome of an appeal. In doing so it has provided insight into the factors that may be considered when determining whether damages may adequately compensate the party that prevails on appeal. It also gives practical guidance on how to manage such stay applications when the first instance court has refused permission to appeal.

Neurim Pharmaceuticals (1991) Ltd and another v Generics (UK) Ltd (trading as Viatris) and another [2022] EWCA Civ 370

Neurim Pharmaceuticals (1991) Ltd and another v Generics (UK) Ltd (trading as Viatris) and another [2022] EWHC 512 (Pat)

Background

The Court of Appeal's ruling (handed down on 29 March 2022) is the most recent in the long-running dispute between Neurim and Mylan. Before discussing the detail of this decision it is necessary to go back to the start:

In February 2020 Neurim sought to restrain Mylan from launching their generic version of Neurim's Circadin (an insomnia treatment) by launching patent infringement proceedings based on EP(UK) 1,441,702 (the "Parent Patent"). At that time Neurim failed to obtain an interim injunction from the High Court (and again at an expedited appeal in June 2020), and so Mylan has been on the market for some time.

That infringement action relating to Parent Patent was at first successful when the Patents Court (Marcus Smith J) found it valid and infringed, but was shortly thereafter brought to an end by the EPO Board of Appeal announcing their opinion that the Parent Patent was invalid for insufficiency. The present action involves an infringement claim in relation to a divisional of that patent (EP(UK) 3,103,443 - the "Divisional Patent") which Neurim have amended to be "patentably indistinct" from its parent.

The first stage of the current action was a trial of preliminary issues (judgment here) which led to findings that Mylan was not issue estopped (because it was prevented from fully pursuing an appeal against the previous decision on the Parent Patent) and that Neurim's behaviour in seeking to obtain a patentably indistinct divisional patent was not an abuse of process. The Patents Court, however, heavily case managed the proceedings and directed that Marcus Smith J should consider Mylan's validity challenge based on the evidence from the Parent Patent trial. See our earlier article on this decision here: Neurim v Mylan: on and on it goes.

The Patents Court decision

This limited "trial"...