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

This is a phase III, open label, randomized study assessing Osimertinib (80 mg, orally, once daily) versus platinum-based doublet chemotherapy (standard of care) in subjects with confirmed diagnosis of Epidermal Growth Factor Receptor (EGFR) mutation positive NSCLC, who have progressed following prior therapy with an approved Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor (EGFR-TKI) agent and whose tumours harbour a T790M mutation within the EGFR Gene. Subjects must be chemotherapy naive and must agree to provide a biopsy for central confirmation of T790 mutation status following confirmed disease progression on their first line EGFR-TKI treatment (e.g. erlotinib, gefitinib or afatinib). Suitable subjects will then be randomized to receive either Osimertinib (80mg orally, once daily) or platinum-based doublet chemotherapy (pemetrexed 500 mg/m2 + carboplatin area under the plasma concentration-time curve AUC 5 or pemetrexed 500 mg/m2 + cisplatin 75 mg/m2) on Day 1 of every 21-day cycle in a 2:1 (Osimertinib: platinum-based doublet chemotherapy) ratio. 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, they will be given the opportunity to begin treatment with Osimertinib 80mg, once daily. These subjects may continue treatment with Osimertinib even after disease progression, as long as they are continuing to show clinical benefit, as judged by the investigator. The primary objective of the study is to assess the efficacy of Osimertinib compared with platinum-based doublet chemotherapy by assessment of Progression Free Survival (PFS), using investigator assessments according to Response Evaluation Criteria in Solid Tumours (RECIST 1.1), as well as asensitivity analysis of Progression Free Survival using Blinded Independent Central Review (BICR).