Although the T790M mutation confers resistance to the inhibitory effects of Tarceva (erlotinib) and Iressa (gefitinib), preclinical data indicate that Exelixis candidate XL647 can potently inhibit this mutation and other mutant forms of epidermal growth factor receptor (EGFR). The drug is designed to simultaneously inhibit the activity of multiple receptor tyrosine kinases, including EGFR, HER2, and vascular endothelial growth factor receptor type 2 (VEGFR2).
Gisela Schwab, senior vice president and chief medical officer at Exelixis, said: “Non-small cell lung cancer patients who present with the T790M mutation or have relapsed after previous benefit from therapy with erlotinib or gefitinib have few treatment options. Our preclinical data suggest that these patients may benefit from treatment with XL647.
“We believe confirmation of these data in this phase II trial would advance the care of these patients while also providing Exelixis with a clear path to late stage development.”
Under an agreement with GlaxoSmithKline, the company has three months to review the data and decide whether to exercise its option to select the compound for further development. If XL647 is selected, Exelixis would receive a substantial selection milestone and potentially would receive commercialization milestones, royalties on product sales and, under certain circumstances, an option to co-promote in North America.