6. Ausführbarkeit

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.