Abstract: The present invention relates to the field of medicine, and specifically to the field of monoclonal antibodies against human IL-17. More specifically, the invention relates to monoclonal antibodies/antagonists of IL-17A, which bind with high affinity to an IL-17 epitope, wherein the antibodies contain amino acid substitutions in hypervariable regions of heavy and light chains. The antibodies according to this invention can be chimeric, humanized or human antibodies or antigen-binding fragments thereof, and can be used as a medicinal agent for treating autoimmune and inflammatory disorders and disorders of cell proliferation and development. The invention also relates to methods for producing said antibodies.

Abstract: The monoclonal IgG-type antibodies were suggested comprising variable domains represented by a combination of VHH-derivative with a variable domain of the light chain VL. Said antibodies can comprise amino acid substitutions at positions 44 and 45 (Kabat numbering) or combinations thereof. Antibodies of the invention possess increased affinity and improved aggregation stability.