6.6. Nacharbeitbarkeit ohne unzumutbaren Aufwand

In T 137/24 the appellant (opponent 2) asserted that the claims of the patent as granted encompassed non-working embodiments because many polypeptide sequences falling under the definition in the claim did not have any enzymatic activity, as evident from Example 5 of the patent in which a number of truncated polypeptides had been tested unsuccessfully. A research project was hence required to test and identify functional polypeptides. Since the patent did not provide any guidance on how the sequences could be changed without losing enzymatic activity, it was an undue burden to find functional polypeptides.

The board observed that, firstly, since the claims required that the genetically modified yeast cells be suitable for producing a cannabinoid or a cannabinoid derivative and the recited polypeptides were also functionally defined by reference to their enzymatic activity, polypeptides without this enzymatic activity did not fall under the scope of the claims.

Secondly, as pointed out in the decision under appeal, generating polypeptide variants as recited in the claims, such as polypeptides comprising an amino acid sequence that has at least 90% sequence identity to SEQ ID NO:110 or SEQ ID NO:100, and testing them for their enzymatic activity, was disclosed in the patent and only required the use of techniques that were routine for the skilled person working in the technical field of recombinant enzyme variants. No evidence to the contrary was submitted by the appellant. The board thus held that the identification of polypeptide sequences falling under the definitions recited in the claims was not an undue burden for the skilled person.

Therefore, the board concluded that the invention as defined in the claims of the main request was sufficiently disclosed in the patent (Art. 83 EPC).

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.