6. Ausführbarkeit

In T 48/24 claim 1 as granted defined a device comprising a "training data generation unit", a "model construction unit" and an "estimation unit". The device was for training and using machine learning for obtaining a "value representing the composition of waste" in a waste pit upon inputting "data of" a captured image of the waste.

The board observed that sufficiency of disclosure had to be assessed for each case individually. The board saw no apparent reason to treat inventions in the field of machine learning differently from other inventions in this regard. According to the board, it went without saying that the implementation of a suitable machine learning model, its training, and whether the trained model can successfully estimate the specified output based on the input parameters as claimed may be important aspects of sufficiency of disclosure of machine learning inventions. However, there were no special requirements and no general rules for assessing whether these aspects were sufficiently disclosed.

With regard to the decisions referred to by the appellant (opponent), the board considered that it was not possible to derive from T 161/18 any general criteria which might be applicable to the present case. Similarly, the board observed that T 1669/21 illustrated the glaring gap between the breadth of the claimed invention and the level of detail in the patent, but did not provide generally applicable criteria required for sufficiently disclosing a machine learning invention. Likewise, the board also pointed out that the considerations in the present case did not imply any universally applicable criteria for assessing sufficiency of disclosure of machine learning inventions.

In the case in hand, the board noted that the patent did not contain a specific example of the claimed invention. That is, it did not disclose any specific combination of certain "data of" captured images and a particular "value representing composition" of the waste in the images, nor did it provide any details on the implementation and training of an exemplary machine learning model, or any information on the achieved accuracy of estimation. In other words, the patent did not contain any concrete, reproducible example of implementation of the invention. Such a specific example was not in itself an absolute requirement for sufficient disclosure, provided that the skilled person was aware of "at least one way" of carrying out the invention in other ways, for example, through the generic disclosure in the patent or the common general knowledge (see R. 42(1)(e) EPC, "using examples where appropriate"). In the present case, however, providing such an example could have demonstrated that the invention was workable at all, at least in this specific case of the example. It could have served as a reference to better understand the claimed invention, its terms and purpose and the achievable or expected level of accuracy.

The board also explained that sufficiency of disclosure required that the invention could be carried out over the whole claimed breadth without undue burden. This requirement had been formulated in decisions across all technical fields (T 149/21). It reflected the general principle that the protection obtained with the patent had to be commensurate with the disclosed teaching. Even if "one way" of performing the invention was disclosed, this would only be sufficient if this disclosure enabled the skilled person to perform the invention over the whole claimed breadth. The patent in suit taught the general idea of using machine learning to infer properties of the waste composition that could be relevant for operating and controlling a waste incineration plant from images of the surface of the waste pit. However, the disclosure was mostly limited to stating a "result to be achieved". The patent left it to the skilled person to select and evaluate combinations of input data and machine learning models for different desired outputs. Each evaluation involved implementing, training and evaluating the selected models. Overall, this resulted in an enormous number of parameter combinations to choose from. Exploring all the possible combinations of these parameters would require a comprehensive research programme and would place an undue burden on the skilled person.

The board concluded that the maintenance of the patent as granted according to the main request was prejudiced by the ground for opposition under Art. 100(b) EPC. Auxiliary requests 1 to 7 were not allowable under Art. 83 EPC either.

In T 878/23 claim 1 of the main request concerned a product claim. The claimed composition comprised an amino acid combination selected from seven combinations containing two or three amino acids selected from cysteine, alanine, lysine and arginine. Claim 1 further specified that the composition contained specified concentrations (amounts) of each of lysine, alanine and arginine (from "8 to 20 wt.%") and cysteine (from "2 to 10 wt.%") based on the composition's total dry weight. Claim 1 thus defined minimum and maximum amounts for each of the four indicated amino acids in the claimed composition. Dependent claim 4 further specified that the composition of claim 1 contained a "total amino acid concentration ... in the range from 3.5 to 36.5 wt%, based on the total dry weight of the composition". Claim 4 added thus a further limit to the composition as defined in claim 1 concerning the used total minimum and maximum concentration (amount) of amino acids.

The board observed that the minimum concentration of amino acids that had to be present in the claimed composition differed between the ranges indicated in claims 1 and 4. The board explained that since a dependent claim (here claim 4) contained more technical features than an independent claim (here claim 1) on which it depended, the subject-matter of a dependent claim was generally more limited than that of the independent one. However, in the case in hand, the compositions specified in claim 4 were broader than those of claim 1, since claim 4 allowed the presence of lower amino acid concentrations in the claimed composition than claim 1. Since the concentration ranges defined in claims 1 and 4 were mutually exclusive, i.e. incompatible, over a substantial part of their ranges, the skilled person could not technically prepare the composition as defined in claim 4 across substantially the whole breadth claimed, even if taking common general knowledge into account. The subject-matter of claim 4 was therefore insufficiently disclosed.

While appellant I (the patent proprietor) admitted that there was an inconsistency between the concentration ranges indicated in claims 1 and 4, it argued that this inconsistency exclusively resulted in a clarity issue (Art. 84 EPC). The board disagreed. The board explained that the decisive issue did not concern an ambiguity of the scope of protection of the claimed invention, as would be the case, for example, if a specific compound would be defined by an unclear parameter. In the case in hand, standard amino acids were used for preparing the claimed composition. These were specified by standard concentration ranges. The methods for determining these concentrations were standard too. Nevertheless, despite these clear instructions in claims 1 and 4, the skilled person could not prepare the claimed composition over substantially the whole breadth of claim 4 due to the at least in part incompatible or mutually exclusive concentration requirements indicated in claims 1 and 4. Claim 4 thus contained no "forbidden area", but an area which could not be prepared for technical reasons.

The board concluded that Art. 100(b) EPC prejudiced the maintenance of the patent as granted. Since the objections under insufficiency indicated above for claim 4 as granted applied likewise to auxiliary requests 1 to 18, the board held that auxiliary requests 1 to 18 did not comply with the requirements of Art. 83 EPC.

In T 0867/23 the board decided on the basis of the patent as granted (main request). Claim 1 was worded as a purpose-limited product claim in accordance with Art. 54(5) EPC. The treatment of "primary negative symptoms of schizophrenia" was a functional feature of claim 1.

The parties were in dispute regarding whether the application as filed made the claimed therapeutic effect plausible, and whether post-published evidence could be taken into account. The question was whether, on the basis of the evidence contained in the application as filed, cariprazine was demonstrated to have the claimed therapeutic effect on primary negative symptoms of schizophrenia.

In support of its reasoning, the board cited G 2/21 (point 77 of the Reasons), in which the Enlarged Board had explained that, in order to meet the requirement of sufficiency of disclosure, "[…] the proof of a claimed therapeutic effect has to be provided in the application as filed, in particular if, in the absence of experimental data in the application as filed, it would not be credible to the skilled person that the therapeutic effect is achieved. A lack in this respect cannot be remedied by post-published evidence..

In the board's view, this statement of the Enlarged Board did not set a new standard for reliance on post-published evidence in the context of sufficiency of disclosure, i.e. a standard which would depart from the previously cited case law summarised in G 2/21 (as noted in T 979/23). Following G 2/21, a reliance on post-published evidence was not ruled out generally in the context of sufficiency of disclosure for second medical use claims. The reliance on post-published evidence could also not be limited to situations in which it served no useful purpose, i.e. cases in which the effect was already convincingly proven in the application to such an extent that the use of post-published evidence, as a superfluous confirmation of the already proven effect, would be of no relevance. The board explained that, in other words, the scope of reliance on post-published evidence was not zero.

In the case in hand, the board considered that the application as filed contained experimental data reflecting an effect on primary negative symptoms of schizophrenia, and thus disclosed the suitability of cariprazine for the claimed therapeutic indication (see T 609/02). Under these circumstances, the board established that post-published evidence D13 could be taken into account to back up the findings in the application as filed.

The board found that D13 confirmed the findings of the patent, and showed improvements in negative symptoms while excluding indirect effects related to positive, depressive, or EPS (extrapyramidal) symptoms as causal factor. Accordingly, D13 supported the conclusion that cariprazine was effective on primary negative symptoms and refuted the appellants' objection that the improvement could relate to secondary negative symptoms. Therefore, the criteria of sufficiency of disclosure were satisfied.