Anti-cd3/anti-cd28 bispecific antigen binding molecules

A bispecific agonistic CD28 antigen binding molecule characterized by monovalent binding to CD28, comprising

• (a) a first antigen binding domain capable of specific binding to CD28,
• (b) a second antigen binding domain capable of specific binding to CD3, and
• (c) a Fc domain composed of a first and a second subunit capable of stable association comprising one or more amino acid substitution that reduces the binding affinity of the antigen binding molecule to an Fc receptor and/or effector function,
• wherein said second antigen binding domain capable of specific binding to CD3 comprises
• (i) a heavy chain variable region (VHCD3) comprising a heavy chain complementary determining region CDR-H1 of SEQ ID NO:
• 2, a CDR-H2 of SEQ ID NO:
• 3, and a CDR-H3 of SEQ ID NO:
• 4, and a light chain variable region (VLCD3) comprising a light chain complementary determining region CDR-L1 of SEQ ID NO:
• 5, a CDR-L2 of SEQ ID NO:
• 6 and a CDR-L3 of SEQ ID NO:
• 7;
• or
• (ii) a heavy chain variable region (VHCD3) comprising a heavy chain complementary determining region CDR-H1 of SEQ ID NO:
• 10, a CDR-H2 of SEQ ID NO:
• 11, and a CDR-H3 of SEQ ID NO:
• 12, and a light chain variable region (VLCD3) comprising a light chain complementary determining region CDR-L1 of SEQ ID NO:
• 13, a CDR-L2 of SEQ ID NO:
• 14 and a CDR-L3 of SEQ ID NO:
• 15;
• wherein the Fc domain is of human IgG1 subclass and comprises the amino acid mutations L234A, L235A and P329G, in each case as numbered according to the Kabat EU index.