Disclosed is an isolated bispecific antibody, or an antigen-binding fragment thereof, having binding specificities for two different antigens, wherein one of the binding specificities is for IL-17A homodimer, IL-17F homodimer and the IL-17A/IL-17F heterodimeric complex, and the second binding specificity is for any other antigen. Said bispecific antibody has heavy chain CDR1 of DYAMH, CDR2 of GINWNSGGIGYADSVKG or GINWSSGGIGYADSVKG and CDR3 of DMGGFGEFYWNFGL or has light chain CDR1 of RASQSVRSYLA, CDR2 or DASNRAT and CDR3 of QQRSNWPPAT, wherein the antibody exhibits (i) a binding affinity of at least 100 pM or less against the IL-17A homodimer, (ii) a binding affinity of at least 300 pM or less against the IL-17F homodimer, (iii) a binding affinity of at least 400 pM or less against the IL-17A/IL-17F heterodimeric complex.
