CABINET CHAILLOT

The decision under appeal is the opposition division's decision rejecting the oppositions against European patent No. 2 493 466. Claim 1, which is the only independent claim, read as follows:
"1. Compound of formula
FORMULA/TABLE/GRAPHIC
which may be in base form or in the form of a hydrate or a solvate,
in combination with prednisone or prednisolone,
for use in treating prostate cancer,
in patients with castration resistant metastatic prostate cancer who have been previously treated with docetaxel based regimen and have prostate cancer that progressed during or after said treatment."
The compound according to claim 1 is also known as cabazitaxel, XRP6258 and RPR-116258A. XRP6258 was known to be cabazitaxel and to have the structure formula shown in claim 1 at the first priority date. Both cabazitaxel and docetaxel are taxane anticancer agents.
In the written opposition and opposition appeal proceedings, the therapeutic indication of metastatic castration-resistant prostate cancer (or castration resistant metastatic prostate cancer, as it is termed in claim 1) was referred to in abbreviated form as mCRPC. This abbreviation, as well as CRPC for castration-resistant prostate cancer, is also used below.
The feature distinguishing the subject-matter of claim 1 from the disclosure of the experimental arm of the TROPIC study (phase III study protocol for cabazitaxel) in D1/D2 is the effective treatment of the claimed therapeutic indication.
Since the claim contains the achievement of the therapeutic effect as a functional technical feature, non-working embodiments are excluded. Hence, the opponents' argument that therapeutic efficacy is not achieved across the scope claimed cannot succeed. 
On this basis, the objective technical problem is 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.
The solution to this problem is the subject-matter of current claim 1, which includes attaining the relevant therapeutic effect as a functional technical feature.
The issue decisive for obviousness is thus whether the person skilled in the art would have had a reasonable expectation of success with regard to the experimental arm of the TROPIC study.
The board is of the view that the skilled person's expectation of success has to be considered in particular in relation to the TROPIC study's primary endpoint, which was overall survival. Success in the context of a clinical study means meeting the primary endpoint.
Starting from the concept of the TROPIC study, including from its experimental arm, the skilled person would still have equated success (in putting the envisaged treatment into practice and solving the objective technical problem) with an increase in overall survival relative to the comparative arm, i.e. with favourable results regarding the primary endpoint.
Thus, to lead to a finding of lack of inventive step, an expectation of success for improved overall survival must have been present.
The boards have developed a large body of decisions dealing with reasonable expectation of success, including in cases of second medical use where clinical studies were announced in the prior art. This case law mainly focuses on balancing positive and negative pointers. As such pointers are necessarily always linked with the individual circumstances of the case at issue, it cannot be concluded, without taking the circumstances of each case into account, whether there would have been a reasonable expectation of success. Thus the probative value of a clinical study announcement always depends on the particular circumstances of the case.
Thus, and contrary to the opponents' argument, the jurisprudence of the boards does not lead to the conclusion that ongoing clinical studies automatically establish a legal presumption of success.
In principle, the board agrees with the statement in T 1437/21 that a prior disclosure that an investigational product (i.e. active agent) for use in the treatment of a particular condition is undergoing a clinical study may preclude that a subsequently claimed invention involving this product for use in the treatment of that specific condition is considered to involve an inventive step, even where the results of the study have not been made available to the public.
However, as also noted in T 1437/21 and T 3165/19, this consideration is not absolute but must be understood in the context of the circumstances of the individual cases underlying those particular decisions. For instance, as set out in T 2963/19, and confirmed in T 1437/21: "...the approval of a clinical study depends on the assessment of the foreseeable risks to the participants in relation to the anticipated benefit in terms of the relevance of the findings, which does not necessarily imply an expected positive outcome and does not represent a scientific advice on the development programme of the investigational product tested".
The approval of a clinical study does, therefore, not necessarily imply an expected positive outcome.
As a consequence, the question of whether there was a reasonable expectation of success must be answered on the basis of the specific circumstances of the case. This requires an evaluation of all the facts available at the relevant date of the contested patent, such as the nature of the active agent under investigation, how far the clinical testing of the active agent(s) had advanced and how much was known about the clinical efficacy, safety and potential toxicities of the active agent(s) in the pertinent therapeutic indication.
In this regard, the present board concurs also with T 1941/21, in which the board held that inventive step over clinical studies (meaning clinical study anouncements) has to be assessed on a case-by-case basis and further that the reasonable expectation of success which "may arise" from the announcement of a clinical study would have to be denied in the presence of negative pointers dissuading the skilled person from pursuing such a study. The board in T 1941/21 then goes on to investigate also the possible existence of positive pointers, which is in agreement with the approach outlined above that all the facts (i.e. negative as well as positive pointers) must be taken into account.
For the individual aspects relevant for the assessment of the presence of a reasonable expectation of success, the present case differs from the situation underlying the decision in T 2506/12. The claimed subject-matter concerned a combination treatment of two drugs, and the relevant prior art disclosed that a clinical phase I study was ongoing to assess the combination treatment. Each of the two drugs was known to have efficacy in the therapeutic indication (ovarian cancer). The relevant question was thus merely to confirm the usefulness of the drug combination and for this reason the board concluded that, in the absence of contrary information on file, there was no reason for the skilled person to expect the combination to fail.
The board is in agreement with the principles that can be derived from the body of case law discussed above and for this reason does not follow T 96/20, where the board held differently that the announcement of a detailed safety and efficacy clinical study protocol for a particular therapeutic and disease alone provided the skilled person with a reasonable expectation of success of this particular therapeutic, unless there was evidence to the contrary in the state of the art. There was however no detailed discussion regarding this aspect and the potential impact of positive and negative pointers.
On account of these considerations and having in mind the objective technical problem as formulated above, the crucial issue in the assessment of inventive step starting from the experimental arm of the TROPIC study thus remains whether, in view of the available information in the prior art, the skilled person had a reasonable expectation that cabazitazel in combination with prednisone would be effective to improve overall survival.
After analysis, the facts brought forward by the opponents as positive pointers would not have given rise to a reasonable expectation of success. In the absence of a reasonable expectation of success, the claimed subject-matter involves an inventive step in the setting starting from the experimental arm of the TROPIC study.
For the reasons set out above, the subject-matter of claim 1 involves an inventive step within the meaning of Article 56 EPC. The same conclusion applies to the dependent claims.
The appeals are dismissed.