UPC Court of Appeal redefines the inventive step test in landmark decision

On 25 November 2025, the Court of Appeal of the UPC issued its decision in cases UPC_CoA_528/2024 and 529/2024, concerning Amgen's PCSK9 antibody patent (EP 3 666 797). Claim 1 of the contested patent concerns a so-called "medical use" claim. The decision marks the Court of Appeal's first decision in a main action, and it provides much needed insight on multiple important issues. Particularly, the judgment offers substantive reasoning on how the UPC assesses if an invention involves an inventive step. 

The dispute concerned cholesterol-lowering products Repatha® and Praluent®. The Central Division of Munich initially revoked the patent in 2024 for lack of inventive step, while EPO's Opposition Division upheld it in May 2025. 

In assessing the inventiveness of the claimed subject matter, the Court first notes that multiple approaches to the assessment of inventive step exist across different jurisdictions. In the words of the UPC, these different approaches, however, should, and generally do, lead to the same conclusions. 

The Court then proceeds to define the approach taken by the UPC. First, when assessing inventive step, the "objective problem" of the invention must be determined. The UPC does this in a way, which is different from the well-known problem-solution-approach used by the EPO. Under the EPO's approach, the first step is to define the closest prior art and then determine the effects of the distinguishing features, i.e. the differences between the closest prior art and the claimed subject-matter. The EPO refers to this as the "objective technical problem". 

The UPC instead defines the "objective problem" by establishing what the invention adds to the state of the art, based on the technical effect(s) that the skilled person on the basis of the application understands is (are) achieved with the claimed invention. Thus, the problem is not based on the differences to the actual closest prior art. 

In determining the objective problem, the UPC takes a "holistic" approach and compares the claim as a whole in context of the description and the drawings, also considering the inventive concept underlying the invention (the technical teaching). 

Based on the defined "problem", the Court states that the claimed solution is obvious if the person skilled in the art - starting from a realistic starting point - would (not could) have arrived at the claimed subject matter. To avoid hindsight, the defined problem must not include any pointers to the claimed invention. Both points comply with the EPO approach. 

A starting point is deemed "realistic" if it would have been of interest to the skilled person wishing to solve the defined problem, e.g. if it discloses features similar to those of the claimed invention and/or addresses the same or a similar problem as that of the claimed invention. Multiple pieces of prior art may be deemed "realistic", and the invention must be inventive when assessed from each of them. This too, is largely in agreement with the EPO approach.

The skilled person requires a pointer or motivation to take a step in a certain direction from the defined starting point to arrive at a certain solution. Again, this is the same approach used by the EPO.

The skilled person would take such a step, if the results of doing so were clearly predictable, or if there was a reasonable expectation of success. The UPC adopts an interesting approach in defining when such an expectation exists. It holds that a reasonable expectation of success exists where the skilled person - based on scientific appraisal - rationally can predict the successful outcome of the deployed step within a reasonable timeframe. 

It is unclear whether the UPC thereby requires the positive outcome to be predictable for the skilled person in order for a reasonable expectation of success to be substantiated. The predictability requirement appears to extend beyond the traditional understanding of a "reasonable expectation". However, it is too early to say, if the threshold for successfully establishing obviousness is thereby significantly raised by leaving out the reference to "reasonable" and exchanging "expectation" with "prediction". We assume that is not intended.

Also, technical or practical difficulties as well as high costs, may discourage the skilled person from attempting a certain solution. This is also different from EPO practice. 

In summary, the approach adopted by the UPC Court of Appeal seems to be more holistic and less rule based than the EPO problem-solution-approach.

Whether in practice this will lead to different decisions is too early to say. 

The Court of Appeal also provides detailed reasoning regarding its claim interpretation and its assessment of sufficiency and added matter. The patent was ultimately upheld by the Court, thereby overturning the impugned decision of the Central Division in Munich. 

It will be interesting to see whether the EPO and the national courts, including the Danish courts, which have so far followed EPO practice, will adopt the new UPC approach to inventive step.