In tyrosine kinase inhibitor-resistant lung tumors, rociletinib and AZD9291 are highly active when T790M is present and modestly active when T790M is absent.
Nevertheless, several lines of evidence indicate that the T790M mutation confers growth advantage to cancer cells, and it was shown that mice expressing tetracycline-inducible EGFR transgenes harboring the T790M mutation develop lung tumors.