| خلاصه مقاله | Chemotherapy, radiotherapy and surgery are three common conventional treatments for cancer that have had a great successes in treatment, but the mortality rate due to cancer still remained high for several reason. Development of new cancer therapies is based on the design of drugs that targets specifically to cancer cells while have minimal adverse effects on normal tissues. Monoclonal antibodies are among the most specific agents that recognize and bind to cancer cell surface antigens. Despite high successes of monoclonal antibodies, they rarely are able to destroy completely cancer cells alone and it is thought they must be connected to a chemical agents or toxins to increase their efficiency. In immunotoxin based targeted therapy the targeting fragments such as antibodies, ligands and peptides conjugated to toxins, enzymes and other toxic agents. Immunotoxin (ITs) are very efficient so that one ITs molecule enough for killing a tumor cell while 10000- 100000 molecules of chemotherapy needed to kill a tumor cell. ITs according to the type of targeted moiety placed in three groups including: ITs based on the ligand, ITs based on the antibody and based ITs. Today, a variety of ITs have been developed which some of them are in the clinical trials. In 1999 the first IT, Denileukin Diftitox, has been approved by the Food and Drug Administration (FDA) for the treatment of cutaneous T cell lymphoma. In this review, various factors that are considered in construction of ITs as targeted moiety and as the toxic moiety have been discussed. |