Bispecific t cell activating antigen binding molecules

A T cell activating bispecific antigen binding molecule comprising

• (a) a first antigen binding moiety which specifically binds to a first antigen;
• (b) a second antigen binding moiety which specifically binds to a second antigen;
• wherein the first antigen is an activating T cell antigen and the second antigen is CEA, or the first antigen is CEA and the second antigen is an activating T cell antigen;
• and
• wherein the antigen binding moiety which specifically binds to CEA comprises a heavy chain variable region, particularly a humanized heavy chain variable region, comprising the heavy chain complementarity determining region (HCDR) 1 of SEQ ID NO:
• 14, the HCDR 2 of SEQ ID NO:
• 15 and the HCDR 3 of SEQ ID NO:
• 16, and a light chain variable region, particularly a humanized light chain variable region, comprising the light chain complementarity determining region (LCDR) 1 of SEQ ID NO:
• 17, the LCDR 2 of SEQ ID NO:
• 18 and the LCDR 3 of SEQ ID NO:
• 19.