Multispecific antibodies

A multispecific antibody, comprising:

• a first light chain and a first heavy chain derived from a first antibody which specifically binds to a first antigen;
• and
• a second light chain and a second heavy chain derived from a second antibody which specifically binds to a second antigen, wherein:
• in the second light chain, the variable domain VL is replaced by the variable domain VH of the second heavy chain and the constant domain CL is replaced by the constant domain CH1 of the second heavy chain;
• and
• in the second heavy chain the variable domain VH is replaced by the variable domain VL of the second light chain and the constant domain CH1 is replaced by the constant domain CL of the second light chain;
• and
• wherein in the constant domain CL of the first light chain the amino acids at position 124 and 123 (numbering according to Kabat) are substituted independently from each other by an amino acid selected from lysine (K), arginine (R) and histidine (H);
• and wherein in the constant domain CH1 of the first heavy chain the amino acids at position 147 and 213 (numbering according to EU index of Kabat) are substituted independently from each other by an amino acid selected from glutamic acid (E) or aspartic acid (D);
• or
• wherein in the constant domain CL of the second heavy chain the amino acids at position 124 and 123 (numbering according to Kabat) are substituted independently from each other by an amino acid selected from lysine (K), arginine (R) and histidine (H);
• and wherein in the constant domain CH1 of the second light chain the amino acids at position 147 and 213 (numbering according to EU index of Kabat) are substituted independently from each other by an amino acid selected from glutamic acid (E) or aspartic acid (D).