A Phase III, Open Label, Randomized Study of Osimertinib versus Platinum-Based Doublet Chemotherapy for Patients with Locally Advanced or Metastatic Non-Small Cell Lung Cancer whose Disease has Progressed with Previous Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Therapy and whose Tumours harbour a T790M mutation within the Epidermal Growth Factor Receptor Gene

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).

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

Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal. All request will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

When a request has been approved AstraZeneca will provide access to the de-identified individual patient-level data in an approved sponsored tool . Signed Data Sharing Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information. Additionally, all users will need to accept the terms and conditions of the SAS MSE to gain access. For additional details, please review the Disclosure Statements at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.