A Molecular Profiling Study of Patients With EGFR Mutation-positive Locally Advanced or Metastatic NSCLC Treated With Osimertinib

Study design This is a phase II, open-label, single-arm tissue and plasma acquisition study assessing the efficacy, safety and underlying resistance mechanisms of osimertinib (80 mg orally, once daily) as first-line treatment in patients with locally advanced or metastatic EGFR mutation positive non-small cell lung cancer who are EGFR tyrosine kinase inhibitor treatment-naïve and eligible for first-line treatment. Participants with EGFR mutation-positive non-small cell lung cancer will be required to consent to 2 mandatory tumour biopsies to be considered for enrolment in this study. The first biopsy will be done prior to initiating treatment with osimertinib and the second biopsy will be obtained any time between Investigator assessed, Response Evaluation Criteria in Solid Tumours version 1.1 (RECIST 1.1)-defined progression and before the start of any new anticancer treatment. A third optional biopsy may be taken during the course of treatment at the Investigator's discretion if the patient consents and if clinically feasible. Tumour tissue and plasma samples will be collected and examined for genetic and non genetic aberrations that may be important in determining response and resistance to the treatment that participants will receive as a part of their cancer care. Patients should continue on osimertinib until progression or until other treatment discontinuation criteria are met. However, if patients continue to show clinical benefit to treatment as judged by the Investigator, patients may continue to receive osimertinib beyond RECIST 1.1-defined progression. Therefore, there is no maximum duration of treatment. Tumour assessments will be performed at baseline and then every 8 weeks from study enrolment until 3.5 years, and then every 10 weeks until RECIST 1.1-defined. Patients will be followed up for a period of 28 days following discontinuation of osimertinib. Target patient population Male and female patients aged 18 years and over with locally advanced or metastatic pathologically confirmed adenocarcinoma of the lung, not amenable to curative surgery or radiotherapy. Patients will have a tumour that harbours one of the EGFR mutations known to be associated with EGFR tyrosine kinase inhibitor sensitivity, either alone or in combination with other EGFR mutations (EGFR mutation status determined by a local laboratory). Patients must be EGFR tyrosine kinase inhibitor treatment-naïve and eligible to receive first line treatment with osimertinib. Osimertinib is an oral, potent, selective, irreversible inhibitor of both EGFR tyrosine kinase inhibitor sensitizing and resistance mutations in non-small cell lung cancer with a significant selectivity margin over wild type EGFR. Osimertinib (80 mg orally, once daily) will be administered. Doses may be reduced to 40 mg if needed.