Current updates on EGFR and HER2 tyrosine kinase inhibitors for the breast cancer

The epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are the members of protein tyrosine kinase family. Their malfunction causes breast cancer (BC). It is the most common type of cancer in women and is the leading cause of death worldwide. In breast cancer therapy, targeting the EGFR and HER2 receptors has brought promising outcomes. Dual inhibition is observed due to homo-heterodimerization of receptors in the EGFR family. Targeting EGFR and HER2 signalling potentiate the signalling blockade. Dual EGFR and HER2 inhibition suppresses additional signalling pathways, the majority of which rely on HER2-heterodimerization. Several possible EGFR and HER2 inhibitors are now being tested in clinical studies for the treatment of breast cancer. Small molecules with various heterocyclic cores have been reported as dual EGFR/HER2 inhibitors. Currently available EGFR/HER2 tyrosine kinase inhibitors (TKIs) exhibit many adverse effects. This review article highlights the occurrence of breast cancer and its therapy. It emphasizes the currently marketed drugs for EGFR, HER2, and their dual inhibition. It further describes the drug candidates in clinical trials. The alternative novel technique, proteolysis-targeting chimeras (PROTACs) is also been discussed. It is a useful method for knocking down a protein of interest in cancer therapy.