Tri- or tetraspecific antibodies

One or more nucleic acid molecules encoding a trispecific or tetraspecific antibody, wherein the antibody comprises:

• a) a light chain and heavy chain of a full length antibody which specifically binds to a first antigen;
• and
• b) a modified light chain and modified heavy chain of a full length antibody which specifically binds to a second antigen, wherein the variable domains VL and VH are replaced by each other, and/or wherein the constant domains CL and CH1 are replaced by each other;
• and
• c) one to four antigen binding peptides fused via a peptide connector to the C- or N-terminus of the light chains or heavy chains of a) and/or b) wherein said antigen binding peptides specifically bind one or two further antigens.

One or more nucleic acid molecules encoding a tetraspecific antibody, wherein the antibody comprises:

• a) a light chain comprising the amino acid sequence of SEQ ID NO:
• 1;
• b) a modified heavy chain comprising the amino acid sequence of SEQ ID NO:
• 2;
• c) a modified light chain comprising the amino acid sequence of SEQ ID NO:
• 3;
• and
• d) a modified heavy chain comprising the amino acid sequence of SEQ ID NO:
• 4.