Antibodies At The EPO

As noted in our recent article, the EPO's amended Guidelines for Examination entered into force on 1 March 2021. One element of the revisions is a more detailed consideration of what is required for a claim to an antibody to be supported by the application, and the new Guidelines confirm the longstanding practice that all six CDR sequences must normally be defined in the claims.

However, the Guidelines also note that the default position can be overturned if suitable evidence is provided. In decision T0941/16 of 16 February 2021, the Boards of Appeal went to great lengths to allow an applicant to submit such evidence. Claim 1 of the patent application on file defined an anti-PSMA antibody by "at least three" specific CDR sequences from the six present in the exemplified murine parent antibody, while an auxiliary request narrowed this to "at least five", so leaving only one CDR undefined. The applicant's position was that routine experimental techniques were capable