Bispecific antibodies with tetravalency for a costimulatory tnf receptor

The bispecific antigen binding molecule of 13, comprising four moities capable of specific binding to 4-1BB, wherein each of said moities comprises a VH domain comprising

• (i) a CDR-H1 comprising the amino acid sequence selected from the group consisting of SEQ ID NO:249 and SEQ ID NO:250,
• (ii) a CDR-H2 comprising the amino acid sequence selected from the group consisting of SEQ ID NO:251 and SEQ ID NO:252, and
• (iii) a CDR-H3 comprising the amino acid sequence selected from the group consisting of SEQ ID NO:253, SEQ ID NO:254, SEQ ID NO:255, SEQ ID NO:
• 256, and SEQ ID NO:257,
• and a VL domain comprising
• (iv) a CDR-L1 comprising the amino acid sequence selected from the group consisting of SEQ ID NO:258 and SEQ ID NO:259,
• (v) a CDR-L2 comprising the amino acid sequence selected from the group consisting of SEQ ID NO:260 and SEQ ID NO:261, and
• (vi) a CDR-L3 comprising the amino acid sequence selected from the group consisting of SEQ ID NO:262, SEQ ID NO:263, SEQ ID NO:264, SEQ ID NO:265, and SEQ ID NO:266.

The bispecific antigen binding molecule 13, wherein each of the moities capable of specific binding to 4-1BB comprises

• (i) a heavy chain variable region VH comprising an amino acid sequence of SEQ ID NO:267 and a light chain variable region VL comprising an amino acid sequence of SEQ ID NO:268,
• (ii) a heavy chain variable region VH comprising an amino acid sequence of SEQ ID NO:269 and a light chain variable region VL comprising an amino acid sequence of SEQ ID NO:270,
• (iii) a heavy chain variable region VH comprising an amino acid sequence of SEQ ID NO:271 and a light chain variable region VL comprising an amino acid sequence of SEQ ID NO:272,
• (iv) a heavy chain variable region VH comprising an amino acid sequence of SEQ ID NO:273 and a light chain variable region VL comprising an amino acid sequence of SEQ ID NO:274, or
• (v) a heavy chain variable region VH comprising an amino acid sequence of SEQ ID NO:275 and a light chain variable region VL comprising an amino acid sequence of SEQ ID NO:276.