Merck Serono v Comptroller-General [2025] EWCA Civ 45

By this appeal Merck Serono invited the Court of Appeal to invoke its post-Brexit powers and depart from the CJEU decision in Santen, thereby opening up the possibility for the granting of SPCs for second medical use patents where an MA had already been granted for an earlier use of the patented medicinal product.

Merck Serono had applied to the UKIPO for an SPC for the product cladribine (based on MA EU/1/17/1212) for the medicinal product ‘mavenclad’, indicated for the treatment of highly active relapsing remitting multiple sclerosis. The application was refused by the UKIPO on the basis that it did not meet the requirements of Article 3(d) of the SPC Regulation, as interpreted by the CJEU in Santen, because earlier MAs had been granted for cladribine (albeit for a different indication, hairy cell leukaemia).

Merck Serono appealed to the Patents Court on various grounds. The appeal was dismissed by Michael Tappin KC ([2023] EWHC 3240 (Ch)), but he granted permission to appeal. Before the Court of Appeal Merck Serono advanced a single ground of appeal, namely that that Santen had been wrongly decided and the Court of Appeal should exercise its post-Brexit powers and depart from it.

The Court of Appeal held that it could not depart from Santen, having previously applied that decision in Newron ([2024] EWCA 1471). However the Court of Appeal also held that even had it not been bound by Newron it would not have been appropriate to depart from the CJEU’s decision in Santen.

Accordingly SPCs remain unavailable where an earlier MA has already been granted for the active ingredient even where the earlier MA is for a different indication.

Anna Edwards-Stuart KC acted for the Respondents, instructed by Government Legal Department.

[2025] EWCA Civ 45

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