UPC News: Brinkhof secures landmark victory for Amgen – UPC Court of Appeal upholds PCSK9 antibody patent and sets inventive step framework

Brinkhof has secured a major victory for Amgen before the Unified Patent Court’s (UPC) Court of Appeal. On 25 November 2025, the Court of Appeal handed down a landmark decision in Amgen v. Sanofi & Regeneron (UPC_CoA_528/2024 and UPC_CoA_529/2024). The Court of Appeal overturned the Munich Central Division’s first instance revocation and confirmed the validity of Amgen’s PCSK9 antibody patent EP 3 666 797. This decision marks an important turning point in the long-running global dispute between Amgen on the one hand and Sanofi and Regeneron on the other, over cholesterol-lowering PCSK9 inhibitors, including Amgen’s Repatha® and Sanofi/Regeneron’s Praluent®.

In its decision, the Court of Appeal provides a comprehensive framework for assessing inventive step at the UPC. It does so in twelve inventive step principles, ranging from establishing the objective problem to a skilled person’s reasonable expectation of success. To name a few:

• The objective problem should be established by what the invention adds to the state of the art, not by looking at the individual features of the claim but considering the inventive concept underlying the invention.
• The Court of Appeal further makes a clear could / would distinction: the question is not whether the skilled person – starting from a realistic starting point – could take the next step, but whether (s)he would do so, prompted by a pointer or as a matter of routine, and thereby arrive at the claimed solution.
• A reasonable expectation of success implies that the skilled person is able to predict rationally, before the start of a research project, the successful conclusion of that project within acceptable time limits. Possible technical or practical difficulties and uncertainties as to whether the desired result will be obtained, may withhold the skilled person from taking the next step. The stronger a pointer towards the claimed solution, the lower the threshold for a reasonable expectation of success may be. The burden of proof for a reasonable expectation of success lies with the party asserting invalidity.

A central reason for reversing the Central Division’s decision, is the Court of Appeal’s assessment of motivation and reasonable expectation of success in the context of a medical use claim. The Court of Appeal held that, although the prior art suggested PCSK9 as a target and antibodies could be made with routine techniques, the skilled person would not have embarked on the claimed antibody approach with a reasonable expectation of achieving a meaningful therapeutic effect for the indications mentioned in the claim. Therefore, the claims were found to involve an inventive step.

Amgen’s team was led by Koen Bijvank, with team members Daan de Lange, Rik Lambers, Jonathan Santman and Roza Rijpkema from Brinkhof, together with Johannes Heselberger and Axel Berger from Bardehle Pagenberg. This victory builds on Brinkhof’s and VOSSIUS & BRINKHOF’s leading role in many of the first UPC cases and confirms our position as a go-to team for complex cross-border life sciences patent litigation before the Unified Patent Court.