Court Of Appeal Dismisses 'Lay Patient' Argument Agreeing Divisional Valid (Neurim v Mylan)

• Published date: 05 July 2022
• Subject Matter: Intellectual Property, Patent
• Law Firm: Marks & Clerk
• Author: Mr Ian Turner

This is the end of the hard-fought UK battle between Neurim and Mylan. The Court of Appeal upheld Mr Justice Marcus Smith's decision that the divisional patent was valid and infringed and so Mylan will now be subjected to a final injunction. The battle will continue in the European Patent Office (EPO), particularly as the parties agreed a cross-undertaking in damages in the event that the EPO revoke the patent (meaning Mylan dropped its application to stay the final injunction pending the EPO decision). However, a further challenge to the divisional patent, by Teva, will continue in the Patents Court. This decision demonstrates the difficulty of arguing a new point or elevating a minor point on appeal and is a further demonstration of why in the UK system it is so important to get the right expert and to produce robust evidence.

Neurim Pharmaceuticals (1991) Ltd and another v Generics (UK) Ltd and another [2022] EWCA Civ 699

What are the practical implications of this case?

This decision brings to a close the long and hard-fought battle between Neurim and Mylan in the UK. Practitioners may be disappointed to hear that the parties agreed to a cross-undertaking in damages to compensate Mylan in the event the EPO revoke the divisional patent and so the point about whether a final injunction can be stayed pending an EPO opposition did not arise. The focus between these parties will therefore now shift to the EPO where opposition proceedings continue (with six opponents). However, the Patents Court recently refused Neurim's preliminary injunction application against Teva (Neurim v Teva[2022] EWHC 954 (Pat)) so they remain on the market; that challenge to the validity of Neurim's divisional patent, on different grounds, will continue.

Mylan's appeal concerned only one ground of invalidity'the so called 'Lay Patient' argument in which Mylan contended that, when properly understood, the data of the patent did not plausibly disclose the claimed effect of melatonin. The challenge to the decision of Marcus Smith J is very specific to the facts of the case and did not raise any new legal issues. However, it is a demonstration of the difficulty a party faces when:

• an issue is elevated to the sole issue on appeal when it was not articulated clearly, and was not the main case, at first instance, and
• the appellant's expert did not come up to proof at trial

What was the background?

In December 2020, Marcus Smith J decided that patent EP (UK) 1 441 702 was valid and...