Bacteria with tumor-targeting capability express, surface displayed, secreted and/or released modified chimeric therapeutic proteins with enhanced therapeutic activity against a neoplastic tissue including solid tumors, lymphomas and leukemias. The bacteria may be attenuated, non-pathogenic, low pathogenic or a probiotic. The chimeric proteins may be protease sensitive and may optionally be further accompanied by co-expression of a secreted protease inhibitor as a separate molecule or as a fusion.