OCEANiC: This study is investigating whether certain tests that predict the likelihood of a cancer recurrence can determine whether people with EGFR-mutant non-small cell lung cancer can safely avoid chemotherapy after their cancer has been completely removed by surgeryA Phase II, Open-label, Multi-centre Clinical Trial on effect of Osimertinib, With or Without Adjuvant Chemotherapy, Guided by Tumour Next Generation Sequencing (NGS) Co-mutation Status and circulating tumour DNA (ctDNA) Detection on disease-free survival in Patients With Stage IIA-IIIA epidermal growth factor receptor (EGFR)-Mutant Non Small Cell Lung Cancer Following Complete Surgical Resection

Exclusion

1. Previous diagnosis of another lung cancer within 5 years prior to registration.
2. Prior systemic treatment for NSCLC including prior EGFR pathway inhibitor treatment.
3. History of hypersensitivity to active or inactive excipients of osimertinib or drugs with a similar chemical structure or class to osimertinib.
4. Post-operative radiotherapy (PORT) planned.
5. Prior radiation to lung and/or mediastinum.
6. Known history of interstitial lung disease (ILD) or drug-induced pneumonitis requiring steroid treatment, or any evidence of clinically active ILD.
7. Treatment with an investigational drug within five half-lives of the compound or 3 months, whichever is greater.
8. Significant history of cardiovascular disease. Any clinically important abnormalities in rhythm conduction or morphology of resting ECG e.g. Complete left bundle branch block, third degree heart block and second degree heart block. Patient with any factors that increase the risk of QTc prolongation or risk of arrhythmic events such as heart failure, electrolyte abnormalities, Congenital long QT syndrome, family history of long QT syndrome or unexplained sudden death under 40 years of age in first degree relatives or any concomitant medication known to prolong the QT interval and cause Torsades de Pointes.
9. Significant history of peripheral vascular or cerebrovascular disease.
10. Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, active hepatitis B, hepatitis C, or HIV. Chronic hepatitis B carrier with undetectable hepatitis DNA level is allowed. Serological testing is not mandatory unless clinically indicated.
11. Refractory nausea and vomiting, chronic gastrointestinal diseases, inability to swallow the formulated product or previous significant bowel resection that would preclude adequate absorption of osimertinib.
12. History of another concurrent active malignancy that requires ongoing treatment.
13. Any condition that, in the opinion of the investigator, would interfere with evaluation of study treatment or interpretation of patient safety or study results.
14. Treatment with prohibited medications which may interact with study treatment.
15. Serious medical or psychiatric conditions that might limit the ability of the patient to comply with the protocol.
16. Pregnancy, lactation, or inadequate contraception. Participants must be post-menopausal, infertile, or use a reliable means of contraception. Participants of childbearing potential must have a negative pregnancy test done within 7 days prior to registration. Participants who are having a sexual relationship in which their partner could become pregnant must have been surgically sterilised or use a (double if required) barrier method of contraception.
17. Involvement in the planning and/or conduct of the study (applies to both NHMRC CTC staff and/or staff at the study site).