Proof-of-concept clinical studies validating AZD9291 as a mutant-selective EGFR kinase T790M inhibitor. Proof-of-concept clinical studies validating AZD9291 as a mutant-selective EGFR kinase T790M inhibitor. A, preliminary pharmacokinetic profile showing mean (+ SD) total plasma levels of AZD9291, AZ5104, and AZ7550 versus time from a cohort of 6 patients with advanced NSCLC after a single dose of AZD9291 mesylate salt, followed by a 7-day washout and then 8 days of once-daily 20 mg oral dosing in AURA phase I study (NCT01802632). B and C, serial computed tomography scans of the chest from patients before and after treatment with AZD9291 in a phase I trial. B, images from a 57-year-old Korean female patient diagnosed with stage IV NSCLC in May 2011. See the main text for details. C, images from a 57-year-old British female never-smoker diagnosed with stage IV lung adenocarcinoma in December 2010. The patient was previously treated with first-line gefitinib for 14 months, achieving a partial response before eventually developing progressive disease. See the main text for details. Darren A.E. Cross et al. Cancer Discovery 2014;4:1046-1061 ©2014 by American Association for Cancer Research