The present invention relates to bispecific antibodies that specifically bind a T-cell activating antigen and a Tumor Antigen (TA), comprising a first Fab fragment and a second Fab fragment, wherein either the variable regions or the constant regions of the second Fab heavy and light chain are exchanged； and wherein the bispecific antibody does not comprise a Fc domain； methods for their production, pharmaceutical compositions containing said antibodies, and uses thereof.
