Definition

An orally bioavailable, central nervous system (CNS) penetrating, mutant-selective covalent inhibitor of epidermal growth factor receptor (EGFR) exon 20 insertion (Ex20ins) activating mutations, with potential antineoplastic activity. Upon oral administration, EGFR Ex20ins inhibitor BLU-451 selectively targets, irreversibly binds to and inhibits the activity of EGFR Ex20ins and some other oncogenic point mutations. This prevents EGFR Ex20ins-mediated signaling. This may induce cell death and inhibit tumor growth in EGFR Ex20ins-overexpressing tumor cells. EGFR, a receptor tyrosine kinase mutated in many tumors, plays a key role in tumor cell proliferation and tumor vascularization. BLU-451 is able to penetrate the blood-brain-barrier (BBB) and may therefore exert its activity against EGFR Ex20ins-driven CNS primary tumors and CNS metastases. BLU-451 does not inhibit the activity of wild-type (WT) EGFR. EGFR Ex20ins are oncogenic driver mutations that constitutively upregulate kinase activity.