The present disclosure provides a pharmaceutical composition for use in combination with administration of a mutated antibody having a mutation, including substitution, deletion, addition or modification, of at least one amino acid in a CH1 region, a CH2 region, a CH3 region, a CL region, or a framework region, wherein the pharmaceutical composition comprises a cell expressing a chimeric receptor, the mutated antibody is capable of binding to the extracellular binding domain of the chimeric receptor via a moiety having the mutation, and the extracellular binding domain does not bind to an antibody free of the mutation.