Mylan gets green light to challenge Neurim melatonin patent
Mylan has been allowed to challenge Neurim's melatonin patent at trial following a ruling by the High Court of England and Wales that the generic drug maker did not contravene the legal principle of estoppel.
Justice Richard Meade handed down his decision in London on Monday, January 24.
In 2020, Neurim sued Mylan for infringement of European Patent (UK) 1,441,702, the parent patent of European Patent (UK) 3,103,443.
Both patents cover Neurim’s commercial product, Circadin, a 2mg prolonged-release melatonin product for the short-term treatment of insomnia in patients who are aged 55 or over.
On December 16, 2020, Justice Marcus Smith held that the ‘702 patent was valid and infringed, but the opposition division of the European Patent Office (EPO) then revoked the patent that month.
On 30 December, 2020, Justice Smith issued his written order, revoking all of the orders made earlier in the month, including his refusal to permit Mylan to appeal.
Neurim’s divisional ‘443 patent was subsequently granted by the EPO on 30 June 2021, with an expiry date of 12 August 2022.
Neurim contended that issue estoppel arising from the earlier main judgment prevented Mylan from challenging the validity of its divisional ‘443 patent.
Estoppel prevents someone from arguing something or asserting a right that contradicts what they previously said or agreed to by law.
Mylan countered that Neurim’s conduct in amending its divisional patent at the EPO was an abuse of process, and it argued that its conduct in seeking to shut out its challenge to the validity of the patent was an abuse of its dominant market position.
In his summary, Justice Meade said the "unusual" nature of the procedural situation meant he had to "tread carefully", before handing the case back to Justice Smith.
But he noted that Justice Smith’s initial judgment had been “trumped” by the TBA decision, meaning that there was no issue estoppel.
Neurim had argued that Mylan could and should have appealed later, especially when it became apparent that Neurim was going to be granted, or likely to be granted, the divisional ‘443 patent.
But Justice Meade contended that despite its initial loss in mid-December, Mylan had emerged as the definite the winner of the 2020 action and he struggled to see how it could meaningfully have “appealed”, because in a sense any “appeal” would have been bound to succeed because the ‘443 patent had been revoked by the EPO.
“Neurim’s arguments in this respect were also unconvincing because it was unable, in my view to identify, in its post-trial written submissions, when I asked, a rational analysis of when Mylan’s time for appealing on this footing revived and expired,” he said.
However, he did caution that the case offered an “important lesson for the future” and he urged that parties in litigation in the patents court where there are parallel EPO proceedings should regard themselves as under a duty to inform the court about scheduling issues and scheduling changes, whether or not they intend to make a case management application themselves and whether or not it suits their strategy.
The court also dismissed Mylan’s abuse of process claims and declined to review the competition law issues.
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