Epidermal Growth Factor Receptor (EGFR) can be activated by point mutations e.g L858R or by deletions in exon19. A subset of non-small cell lung cancer (NSCLC) have activated EGFR and can be successfully treated with EGFR inhibitors such as erlotinib. However, resistance frequently develops to these inhibitors, often due to acquisition of a further T790M mutation in EGFR leading to relapse. Methods to improve response and delay resistance are therefore of value.
Inhibition of the chaperone, HSP90, leads to the depletion of many client proteins, including EGFR, and has the capacity to simultaneously affect many signalling pathways, offering an alternative strategy for targeting EGFR-driven disease.
AT13387 is a potent, second generation HSP90 inhibitor currently being tested in Phase 2 clinical trials. Here we investigated the effects of combining AT13387 and erlotinib in models of EGFR- driven NSCLC.