The present disclosure provides a low pH pharmaceutical composition comprising (a) an antibody constructs comprising a first domain binding to a target cell surface antigen, a second domain binding to a second antigen and preferably a third domain, which is a specific Fc modality, (b) at least one buffer agent, (c) at least one saccharide, and (d) at least one surfactant； and wherein the pH of the pharmaceutical composition is in the range of 3.5 to 6.
