Osimertinib for Advanced EGFR-positive NSCLC Patients

To evaluate the efficacy (Objective Response Rate), safety and tolerability of 80mg Osimertinib eod dosing in NSCLC patients with sensitizing EGFR mutations and/or EGFR T790M resistance mutation that have no prior EGFR treatment. To investigate the efficacy and safety of Osimertinib 80mg/eod. Parameters like PFS, DoR, the incidence of brain metastases and OS will be assessed for the efficacy using RECIST criteria version 1.1. PFS in the brain will be another endpoint. Adverse events will be graded according to CTCAE v4.0 by recording vital signs, physical examinations, weight, ECG, ECOG performance status, clinical chemistry, haematology, urinalysis. We would use ctDNA to detect the mutations and compare the progress of the disease or the outcome of patients besides clinical assessments. The relationship between PK and selected efficacy, pharmacodynamic markers (like duration of inhibition of EGFR by hair follicle sampling) and safety endpoints will be assessed as well.