6.1.1 5.6.1.1 Definition by structure of the antibody

In order to fulfil the requirements of Art. 84, the structural definition of an antibody must contain at least the sequence of each of the CDRs required for binding to the antigen, which, in the case of an IgG, is CDRs 1-3 of each of the variable domains.

Hence, if an IgG is defined by fewer than its six CDRs, the claim will be objected to under Art. 84 because it lacks essential technical features unless it is experimentally shown that one or more of the six CDRs do not interact with the antigen.

If CDRs are not defined by their specific sequence, but by reference to a larger heavy or light chain sequence, the numbering scheme, for example Kabat, Chothia or IMGT, must also be indicated.