Anti-CD22 antibodies, their immunoconjugates and their uses

An immunoconjugate comprising an antibody or an antigen-binding fragment thereof covalently linked with a cytotoxic agent, wherein the antibody or the antigen-binding fragment thereof is a monoclonal antibody or an antigen-binding fragment thereof. bind with CD22 and comprise a heavy chain variable domain having the amino acid sequence of SEQ ID NO: 16, and a light chain variable domain having the amino acid sequence of SEQ ID NO: 18, and wherein the antibody or the antigen-binding fragment thereof further comprise a cysteine at position 205 of the light chain according to the Kabat numbering convention or position 118 of the heavy chain according to the US numbering convention.