8. Das Verhältnis zwischen Artikel 83 und Artikel 84 EPÜ

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.