Insufficiency Arising From A Partially Incompatible Dependent Claim

Dependent claims are a key part of a claim set, although they are often given less attention than the independent claims. However, they can play a vital role in EPO opposition and appeal proceedings by providing useful fallback positions, particularly given that opponents cannot raise lack of clarity against the features of the granted claims. Moreover, it seems from a recent EPO Board of Appeal decision T 0878/23 that the dependent claims can also be crucial to the validity of an entire claim set and should perhaps be given more attention.

Background of decision T 0878/23
The case relates to a patent granted with an amended claim 1 directed towards a composition comprising a carrier material comprising a polysaccharide, at least one antioxidant and an amino acid combination selected from various specific combinations of two or three of cysteine, alanine, lysine and arginine. Claim 1 then specified that the amino acids lysine, alanine and arginine are each present