The European Patent Office (EPO) has a well-established approach to the assessment of inventive step – the “Problem-Solution” analysis. When the Unified Patent Court (UPC) opened its doors on 1 June 2023, it was uncertain whether or not the UPC would follow the EPO inventive step approach. There were early indications from the courts of first instance that the UPC would go its own way with inventive step. However, in other cases, the UPC judges appeared to apply the EPO Problem-Solution approach.
In November 2025, the UPC Court of Appeal handed down two decisions – Amgen v Sanofi and Meril v Edwards, which now provide a clear framework for the assessment of inventive step at the UPC. Below, we compare and contrast the EPO and UPC, highlighting similarities and differences between the approaches applied.
The General Approach
EPO
The EPO applies the Problem-Solution approach, which is presented in the EPO Guidelines as the following three stages:
(i) determining the “closest prior art”;
(ii) establishing the “objective technical problem to be solved”; and
(iii) considering whether or not the claimed invention, starting from the closest prior art and the objective technical problem, would have been obvious to the skilled person.
UPC
The UPC’s inventive step approach can also be divided into three core steps:
(i) establishing the objective problem to be solved;
(ii) identifying one or more “realistic starting points”; and
(iii) assessing obviousness based on considering whether the skilled person, starting from a realistic starting point and wishing to solve the objective problem would have arrived at the claimed solution.
The Starting Point
EPO
The first step in the EPO approach is the identification of a disclosure representing the “closest prior art” (CPA). The EPO Guidelines define the CPA as a single reference disclosing the combination of features which represent the most promising starting point for a development leading to the invention. The CPA is typically selected on the basis that it is directed to a “similar purpose or effect” as the invention. It is accepted by the EPO that there may be more than one CPA reference. A finding of inventive step requires an invention to be non-obvious (based on application of the problem-solution approach) starting from any viable CPA reference.
UPC
In contrast to a CPA reference, the UPC bases its inventive step assessment on a “realistic starting point”. The UPC Court of Appeal has confirmed that: “A starting point is realistic is the teaching thereof would have been of interest to a skilled person who, at the relevant date, wishes to solve the objective problem.” It has also confirmed that, like the CPA, there may be more than one realistic starting point and the claimed invention must be inventive starting from each of them.
In practice, there may be little distinction between the EPO’s choice of CPA and the UPC’s choice of a realistic starting point. The important point to note however, is that the EPO’s problem-solution approach is driven by the CPA (and can therefore differ starting from different CPA references); in contrast, the UPC’s starting point appears to play a lesser role in setting up the objective problem to be solved. This is explained in more detail below.
The problem to be solved
EPO
At the EPO, the formulation of the “objective technical problem” (OTP) depends heavily on the selection of the CPA. In particular, it is first necessary to compare the CPA with the claimed subject-matter and identify the distinguishing feature(s) of the invention, and secondly, to identify the technical effect arising from the distinguishing feature(s). This technical effect is the foundation for formulating the OTP. The EPO makes clear that the problem, as formulated, must not contain a pointer to the solution i.e., the claimed invention.
UPC
Under the UPC’s approach, the objective problem, although referred to as “objective”, is not formulated starting from a single prior art document. The UPC Court of Appeal has explained that the object of the invention i.e., the objective problem, must be determined by “establishing what the invention adds to the state of the art, not by looking at the individual features of the claim, but by comparing the claim as a whole in context of the description and the drawings, thus also considering the inventive concept underlying the invention (the technical teaching), which must be based on the technical effect(s) that the skilled person on the basis of the application understands is (are) achieved with the claimed invention.”
It is clear from the above, that the “technical effect” is important in formulating the objective problem under both the EPO and UPC approaches. However, at the EPO, the technical effect relied upon must be linked to the distinguishing feature(s) vis-à-vis the CPA, whereas the UPC approach is more holistic, requiring the skilled person to think about the technical effect achieved by the claimed invention as a whole. Both the EPO and UPC have also been clear that in formulating the objective problem, there should be no pointers to the solution i.e., the claimed invention.
The assessment of obviousness
EPO
The EPO Guidelines state that in step (iii) of the problem-solution analysis: “the question to be answered is whether there is any teaching in the prior art as a whole that would (not simply could, but would) have prompted the skilled person, when faced with the objective technical problem, to modify or adapt the closest prior art in the light of that teaching in such a way as to arrive at something falling within the terms of the claims and thus achieve what the invention achieves.” The notion of there being a “reasonable expectation of success”, based on the teaching of the prior art, in achieving the promise of the claimed invention is also an important principle established by EPO case law.
UPC
The UPC’s approach to the assessment of obviousness is very much aligned with EPO principles.
The UPC Court of Appeal has stated that: “A claimed solution is obvious if the skilled person would have taken the next step in expectation of finding an envisaged solution of his technical problem. This is generally the case when the results of the next step were clearly predictable, or where there was a reasonable expectation of success.”
It is, of course, a fundamental requirement for a finding of inventive step that an invention is not obvious to a person skilled in the art when considering the state of the art. The approach taken by any Court or Patent Office to the assessment of inventive step is ultimately seeking to answer this question. The EPO’s problem-solution approach, for example, is simply a means by which the obviousness assessment can be caried out in a structured way. The fact that both the EPO and UPC approaches culminate in an assessment of obviousness that is founded in the same principles provides reassurance that there can be harmonisation between the approaches.
Summary
The EPO’s Problem-Solution approach to inventive step is often considered a rigid, formulaic approach, with the analysis heavily influenced by the selection of CPA and the difference(s) in claimed subject-matter stemming therefrom. The UPC’s approach is considered a more ‘holistic approach’, based on analysis of the claimed subject-matter as a whole and thinking about what the invention adds to the state of the art. Whether these two approaches will regularly result in different outcomes in terms of the overall conclusion on inventive step, as with Sanofi’s patent EP2493466 discussed in our article here, for example, remains to be seen. However, we hope that the EPO and UPC will arrive at a harmonised analysis of inventive step, notwithstanding the different approaches, since it would clearly result in frustration for users of both systems if disagreement were a frequent occurrence.
