This invention pertains to a TNF alpha-binding polypeptide composition comprising at least one of a modified heavy chain variable region polypeptide or a modified light chain variable region polypeptide that is capable of specifically binding to human TNF alpha. The modified heavy and light chain variable region polypeptides of the TNF alpha binding polypeptide are modified by at least one amino acid residue substitution, deletion or addition and are homologous to the heavy and light chain variable regions, respectively, of a non-human monoclonal antibody that specifically binds human TNF alpha. The polypeptide compositions of the invention comprising modified heavy and light chain variable region polypeptides are less immunogenic in a human than are the homologous heavy and light chain variable region polypeptides from a non-human animal.