The present invention provides a pharmaceutical composition comprising a bispecific single chain antibody construct. Said bispecific single chain antibody construct is characterized to comprise or consist of at least two domains, whereby one of said at least two domains specifically binds to human EpCAM and comprises at least one CDR-H3 region comprising the amino acid sequence NXID antigen and a second domain binds to human CD3 antigen. The invention further provides a process for the production of the pharmaceutical composition of the invention, a method for the prevention, treatment or amelioration of a tumorous disease and the use of the disclosed bispecific single chain antibody construct and corresponding means in the prevention, treatment or amelioration of a tumorous disease.