This decision comes after the UPC Court of Appeal confirmed that it will adopt a holistic assessment of inventive step, moving away from the EPO’s problem-solution approach. Despite assurances that when applied properly both approaches should lead to the same outcome, in this instance this was not the case.

This article compares the approaches taken by the EPO Board of Appeal and the UPC Munich Local Division and discusses the factors that led to these diverging outcomes.

Background 

Claim 1 of Sanofi’s EP2493466 patent is directed to cabazitaxel in combination with prednisone or prednisolone for use in the treatment of patients with castration resistant metastatic prostate cancer (mCRPC) that have previously been treated with a docetaxel-containing regimen.

The patent disclosed the results of a phase III study which compared cabazitaxel in combination with prednisone, with mitoxantrone in combination with prednisone in mCRPC patients.

Particularly, the results indicated that the median overall survival of patients receiving cabazitaxel was improved by 2.4 months compared to patients receiving mitoxantrone. This was observed even in the arm of patients who had previously not responded to docetaxel.

The patent also mentioned other criteria that were in cabazitaxel’s favour, such as the prostate-specific antigen (PSA) response rate, the tumour response rate, the pain response rate, as well as the duration without progression of the tumour, without progression of the PSA and without progression of the pain.

The key prior art was as follows:

• the clinical trial protocol of the phase III trial (without data). The end date indicated that the trial was nearly complete at the priority date of the patent;
• a phase I study for cabazitaxel involving 25 patients, only eight of whom had prostate cancer and only two of these patients showed a partial response. Further, only one of these two had received a prior treatment of docetaxel;
• a phase II study for cabazitaxel on breast cancer patients who had received a prior treatment with a taxane anti-cancer agent, 65% of whom had received docetaxel. Favourable results were observed, however this line of development was discontinued, and no phase III study occurred.

Test for inventive step 

The Munich Local Division applied the definitive test recently set out in Meril v Edwards and Amgen v Sanofi. The key differences in this test compared with the EPO’s problem-solution approach lie in the formulation of the “objective problem” as the first step, and so the problem is derived from the patent itself in isolation of the prior art, and the selection of the “realistic starting point” as opposed to “closest prior art”. We discuss the similarities and differences of each approach in detail in our article reporting the above decisions (see dycip.com/upc-inventive-step-definitive-test).

In the present case, both the Board of Appeal and Munich Local Division considered the  closest prior art or realistic starting point was considered to be the phase III protocol, with the difference being whether the claimed therapeutic effect had been achieved.

However, the Board of Appeal then went on to formulate the objective technical problem as “to put into practice the effective treatment of prostate cancer with cabazitaxel in co-administration with prednisone in patients with mCRPC who have been previously treated with a docetaxel-based regimen and who have prostate cancer that progressed during or after that treatment”.

In contrast, the Munich Local Division formulated the objective problem more broadly as “to provide a therapeutic option for treating patients suffering of castration resistant metastatic prostate cancer who have been previously treated with docetaxel-based regimen and have prostate cancer that progressed during or after that treatment”. It appeared to put weight on the fact that the data in the patent showed a range of other therapeutic effects, not just overall survivability. Thus, “a therapeutic option” included both increased overall survival and palliative treatment.

Reasonable expectation of success 

The difference in formulation of the problem to be solved also affected the standard used to assess whether the skilled person had a reasonable expectation of success.

The Board of Appeal asserted that this had to be assessed in the context of achieving the primary end point of the phase III trial, which was improved overall survivability. The Munich Local Division disagreed, noting that the objective problem was not limited to the primary endpoint of the phase III trial but also included palliative treatment. Thus, the patent would be obvious if the skilled person had a reasonable expectation of success of achieving either of these outcomes.

Both decisions assessed whether there was a reasonable expectation of success largely in the same way. Both agreed that ongoing clinical studies does not automatically establish a reasonable expectation of success and each case must be assessed based on its specific circumstances. Both also came to their decision on the basis of balancing positive and negative pointers. `

Of particular note was the contrasting view the respective forums took of the data that was available for cabazitaxel prior to the priority date.

The Board of Appeal considered that the phase I and phase II data were limited such that the phase III study could not be considered a confirmatory study. It appeared to put considerable weight on the lack of data in prostate cancer patients, considering that overall survival is linked to type of cancer and stage of disease progression, and that the phase I data are not the type to allow any insight into overall survivability.

Taking all pointers into account, the Board of Appeal concluded that there was no reasonable expectation of success, and so the invention could not be considered obvious.

In contrast, the Munich Local Division did acknowledge the limitations of the data but ultimately considered that the fact that there was a phase III trial that was almost complete did give the phase I data in a single patient more weight. It also considered that although the phase II data were in a different patient group, the results were encouraging and demonstrated that cabazitaxel could be used in the treatment of the claimed patient group, that is, those who are resistant to a first taxane, namely docetaxel.

Taking all pointers into account, it concluded that there was “no evidence against cabazitaxel’s efficacy in the treatment of mCRPC as a second-line treatment after a docetaxel regimen has been discontinued” and so considered there was a reasonable expectation of success such that the patent was obvious.

Summary 

At first glance, it would be reasonable to assume that the difference in outcomes results from the broader formulation of the objective problem and standard for a reasonable expectation of success by the UPC. However, the Munich Local Division’s final comments of “the person skilled in the art would have considered that…the second-line cabazitaxel plus prednisone experiment in progress in a phase III trial for more than three years, had a reasonable chance of showing a favourable effect including the (moderate) increase in survival” appear to indicate that even if they had used the same problem and standard for a reasonable expectation of success as the Board of Appeal, the outcome would have still been the same.

The real difference appears to be in the Munich Local Division’s willingness to consider the overall trajectory of the relevant clinical trial data and progress, indicating a more plausibility-based approach to a reasonable expectation of success, and arguably a lower bar when clinical trial protocols are concerned.

With the possibility of appeal for Sanofi before the UPC, and petition for reviews pending before the EPO, it will be interesting to see whether these diverging decisions will remain. 

Case details at a glance

Jurisdiction: UPC
Decision level: Munich Local Division
Parties: Sanofi SA as successor of Sanofi Mature IP and others (claimant) v STADAPHARM GmbH and others (defendant)
Citations: UPC_CFI_146/2024 - UPC_CFI_496/2024, UPC_CFI_147/2024 - UPC_CFI_374/2024, UPC_CFI_148/2024 - UPC_CFI_503/2024
Date: 12 December 2025
Decision: dycip.com/upc-cfi-146-2024

Jurisdiction: EPO
Decision level: Technical Board of Appeal
Parties: SANOFI v Glenmark Pharmaceuticals Europe Ltd, Accord Healthcare Ltd, Zentiva ks, Fresenius Kabi Deutschland GmbH, Dr Reddy’s Laboratories Ltd/Betapharm Arzneimittel GmbH, Generics (UK) Limited and Vossius & Partner 
Citation: T 0136/24
Date: 03 June 2025
Decision: dycip.com/epo-t-0136-24 

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Inventive step at the UPC - Court of Appeal sets definitive test.