7. Expectation of success, especially in the field of genetic engineering and biotechnology
7.1. Reasonable expectation of success
In accordance with the case law of the boards of appeal, a course of action can be considered obvious within the meaning of Art. 56 EPC if the skilled person would have carried it out in expectation of some improvement or advantage (T 2/83, OJ 1984, 265). In other words, obviousness is not only at hand when the results are clearly predictable but also when there is a reasonable expectation of success (T 149/93). It is not necessary to establish that the success of an envisaged solution of a technical problem was predictable with certainty. In order to render a solution obvious it is sufficient to establish that the skilled person would have followed the teaching of the prior art with a reasonable expectation of success (T 249/88, T 1053/93, T 318/02, T 1877/08, T 2168/11, T 867/13, T 3103/19), which is to be assessed on a case-by-case basis.
In some decisions, especially in the field of biotechnology, the boards have asked whether in the cases in point it was obvious for the skilled person to try a suggested approach, route or method with a reasonable expectation of success (T 60/89, OJ 1992, 268). For more about biotechnological inventions and the definition of the skilled person, see also chapter I.D.8.1.4 below.
In T 2168/11 the board referred to the case law, according to which the expectation of success depended on the complexity of the technical problem to be solved. While for very ambitious problems requiring the consideration of all the features relied on by the respondent (patent proprietor) but not contained in claim 1, important difficulties might be expected a priori, less ambitious problems might normally be associated with higher expectation of success (see T 192/06, T 782/07, T 688/14, T 967/16). In T 967/16 the board found that the expectations of a skilled person for the value of the claimed correlation between the HLA-B*1502 allele and the adverse drug reaction SJS/TEN developed in response to, or associated with, the OXC or LIC treatment could be as high as 100% but also as low as 47% or even lower than those reported in document (4) for other aromatic anticonvulsants less, or not at all, related to CBZ. In this sense, the board found that the formulated technical problem was not very ambitious and thus, the skilled person had a high expectation of success.
In line with T 918/01, the board in T 1577/11 concluded that, given the superior efficacy of anastrozole, as compared with tamoxifen, in treating advanced breast cancer, there was a reasonable expectation it would also improve the treatment of early breast cancer, as compared with that achieved with tamoxifen.
In T 1680/17 the board considered that the skilled person would not have turned to formulations used in basic research when aiming at providing a formulation for therapeutic treatment. The requirements of a formulation to be used in basic research were fundamentally different from the requirements of a formulation to be administered to a patient.
In T 96/20 the board considered that the announcement of a detailed safety and efficacy clinical trial protocol for a particular therapeutic and disease provided the skilled person with a reasonable expectation of the success of this particular therapeutic, unless there was evidence to the contrary in the state of the art. The board failed to see how the mere fact that no myasthenia gravis therapy had been approved for a long time would have diminished the expectation of success for the specific clinical trial disclosed in the prior art.
In T 1941/21 the board noted that clinical trials were usually initiated on the basis of encouraging results from preclinical experiments. Thus, the announcement of a phase II clinical trial protocol for a particular therapeutic agent and a disease might provide the skilled person with a reasonable expectation of success. The board held, however, that such reasonable expectation of success was to be denied in a situation where a skilled person would have been discouraged from carrying out the clinical trials, such as when the state of the art provides the skilled person with reasons for not pursuing the solution envisaged in the clinical trial or provides the skilled person with an expectation of failure.
- T 0136/24
In case T 136/24, the therapeutic effect of claim 1 was the treatment of prostate cancer in the specified patient group. Claim 1 was intended to define a new treatment option for mCRPC patients in the form of a cabazitaxel-based combination treatment.
The phase III clinical study (TROPIC) presented in the application was addressed with very detailed reasons in respect of assessment of sufficiency of disclosure, novelty and inventive step. Concerning inventive step, given the TROPIC study as the starting point and the formulation of the technical problem in view of the claimed therapeutic effect being credible, the issue decisive for obviousness was 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 opponents argued that, for a second medical use claim, where the prior art disclosed that a clinical study with the same active agent(s) for the same therapeutic indication had been proposed or was underway, a reasonable expectation of success was generally implied by the mere fact that the study had been authorised, unless there was some evidence of a dissuading teaching in the prior art. In other words, the announcement of a clinical study established a legal presumption of reasonable expectation of success. No dissuading element (negative pointer) was known in the prior art. In addition, the opponents mentioned positive pointers..
The board was not convinced. The skilled person's expectation of success had 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. The board reviewed the 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 focused on balancing positive and negative pointers. The probative value of a clinical study announcement always depended on the particular circumstances of the case. Thus, contrary to the opponents' argument, the analysis of the jurisprudence of the boards did not lead to the conclusion that ongoing clinical studies automatically establish a legal presumption of success..
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. The case in hand related to a new cancer drug used in a new indication, and the situation was complicated by the further issue of resistance to taxanes. The crucial issue was whether, in view of the available information in the prior art, the skilled person had a reasonable expectation that cabazitaxel in combination with prednisone would be effective to improve overall survival..
The board examined in detail the positive pointers (a) to (f) and on this occasion inter alia addressed that under usual circumstances, the fact that a phase III clinical trial was carried out might indeed provide a pointer indicating a successful development path of a new drug/new drug application, however in the case in hand, the usual path of drug development was only poorly reflected. The board also stated that the fact that a study was nearing completion per se, in the absence of knowledge of the parameters selected for monitoring, was neither a positive nor a negative pointer when assessing expectation of success. In conclusion, the facts brought forward by the opponents as positive pointers would not have given rise to a reasonable expectation of success.