Immunotoxins, an advance tool for cancer treatment: Review and update

Abstract

Conventional therapeutic approaches like chemotherapy, surgery, and radiation for cancer and other malignancies have a limited success rate. Several factors such as drug resistance, non-penetrability into solid tumors and unwanted toxicity due to non-specific action contribute to treatment failure. To overcome these issues, immunotoxins were developed having a target-specific action. Immunotoxins are chimeric cytotoxic proteins which are formed by linking a toxin moiety to intact antibody or its fragment. Bacterial and plant-based toxins are used in immunotoxins construction but they have many drawbacks in terms of immunogenicity and non-specific toxicity. Recently, a novel class of immunotoxins of human origin has been introduced. Immunotoxins fight back cancers by targeting the neoplastic cells and cause cells death by inhibiting protein synthesis. They have been categorized into two main classes, chemically conjugated immunotoxins and recombinant immunotoxins. The aim of this work is to present recent advances in immunotoxins development and a comprehensive illustration of Immunotoxins sources along with their generations. Moreover, it also summarizes the information regarding future directions to be explored as well as the limitations in immunotoxins development and its use.