Bispecific antigen binding molecules comprising anti-4-1BB clone 20H4.9

A bispecific antigen binding molecule, comprising:

• two or four antigen binding domains that are Fab fragments each capable of specific binding to 4-1BB;
• an IgG Fc domain composed of a first and a second subunit capable of stable association;
• a VH and VL domain capable of specific binding to Fibroblast Activation Protein (FAP), wherein the VH domain is connected via a peptide linker to the C-terminus of one of the two first and second subunits and wherein the VL domain is connected via a peptide linker to the C-terminus of the other of the first and second subunits;
• and
• wherein the two or four antigen binding domains capable of specific binding to 4-1BB comprise two heavy chain and two light chain variable regions, or four heavy chain and four light chain variable regions, respectively, wherein:
• (i) the heavy chain variable region (VH4-1BB) comprises:
• (i) CDR-H1 comprising the amino acid sequence of SEQ ID NO:1, (ii) CDR-H2 comprising the amino acid sequence of SEQ ID NO:2, and (iii) CDR-H3 comprising the amino acid sequence of SEQ ID NO:3, and
• (ii) the light chain variable region (VL4-1BB) comprises (iv) CDR-L1 comprising the amino acid sequence of SEQ ID NO:4, (v) CDR-L2 comprising the amino acid sequence of SEQ ID NO:5, and (vi) CDR-L3 comprising the amino acid sequence of SEQ ID NO:6.