Disclosed herein are humanized antibodies, antigen-binding fragments thereof, and antibody conjugates, that are capable of specifically binding to certain biantennary Lewis antigens, which antigens are expressed in a variety of cancers. The presently disclosed antibodies are useful to target antigen-expressing cells for treatment or detection of disease, including various cancers. Also provided are polynucleotides, vectors, and host cells for producing the disclosed antibodies and antigen-binding fragments thereof. Pharmaceutical compositions, methods of treatment and detection, and uses of the antibodies, antigen-binding fragments, antibody conjugates, and compositions are also provided.
