AZD9291 (Osimertinib) Versus Platinum-Based Doublet-Chemotherapy in Locally Advanced or Metastatic Non-Small Cell Lung Cancer

Inclusion Criteria: * Subjects with histologically or cytologically documented NSCLC. * Locally advanced or metastatic NSCLC * Radiological documentation of disease progression following 1st line EGFR TKI Treatment without any further treatment * Eligible to receive treatment with the selected doublet-chemotherapy * Central confirmation of T790M+ mutation status * World Health Organization (WHO) performance status 0-1 * At least one lesion, not previously irradiated. Exclusion Criteria: * • Prior neo-adjuvant or adjuvant chemotherapy treatment within 6 months prior of starting 1st EGFR TKI treatment * Treatment with more than one prior line of treatment for advanced NSCLC * Treatment with an approved EGFR-TKI (e.g.,erlotinib, gefitinib, afatinib) within 8 days or approximately 5x half-life of the first dose of study treatment * Any investigational agents or other anticancer drugs from a previous treatment regimen or clinical study within 14 days of the first dose of study treatment * Previous treatment with Osimertinib, or a 3rd generation EGFR TKI For subjects who cross-over to Osimertinib: * Once subjects on the platinum-based doublet chemotherapy arm are determined to have objective radiological progression according to RECIST 1.1 by the investigator and confirmed by independent central imaging review. * At least 14 days since last dose of platinum-based doublet chemotherapy