Inclusion Criteria:

          1. Male or female, at least 18 years of age; patients from Japan at least 20 years of
             age.

          2. Pathologically confirmed non-squamous Non-Small Cell Lung Cancer (NSCLC).

          3. Newly diagnosed locally advanced (clinical stage IIIB, IIIC) or metastatic Non-Small
             Cell Lung Cancer (NSCLC) (clinical stage IVA or IVB) or recurrent Non-Small Cell Lung
             Cancer (NSCLC) not amenable to curative surgery or radiotherapy.

          4. The tumor harbors 1 of the 2 common epidermal growth factor receptor (EGFR) mutations
             known to be associated with Epidermal growth factor receptor tyrosine kinase
             inhibitors (EGFR-TKI) sensitivity (Ex19del or L858R), either alone or in combination
             with other epidermal growth factor receptor (EGFR) mutations, which may include T790M.

          5. Patients must have untreated advanced Non-Small Cell Lung Cancer (NSCLC) not amenable
             to curative surgery or radiotherapy.

          6. WHO PS of 0 to 1 at screening with no clinically significant deterioration in the
             previous 2 weeks.

          7. Life expectancy >12 weeks at Day 1.

          8. Willing to use contraception as appropriate during the study and for a period of time
             after discontinuing study treatment.

        Exclusion Criteria:

          1. Spinal cord compression; symptomatic and unstable brain metastases, except for those
             patients who have completed definitive therapy, are not on steroids, and have a stable
             neurological status for at least 2 weeks after completion of the definitive therapy
             and steroids.

          2. Past medical history of Interstitial Lung Disease (ILD), drug-induced Interstitial
             Lung Disease, radiation pneumonitis that required steroid treatment, or any evidence
             of clinically active Interstitial Lung Disease.

          3. Any evidence of severe or uncontrolled systemic diseases, including uncontrolled
             hypertension and active bleeding diatheses, which in the Investigator's opinion makes
             it undesirable for the patient to participate in the trial.

          4. QT prolongation or any clinically important abnormalities in rhythm.

          5. Inadequate bone marrow reserve or organ function as demonstrated by any of the
             following laboratory values:

          6. 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.

          7. Prior treatment with any systemic anti-cancer therapy for advanced Non-Small Cell Lung
             Cancer (NSCLC) not amenable to curative surgery or radiation including chemotherapy,
             biologic therapy, immunotherapy, or any investigational drug. Prior adjuvant and
             neo-adjuvant therapies (chemotherapy, radiotherapy, immunotherapy, biologic therapy,
             investigational agents), or definitive radiation/chemoradiation with or without
             regimens including immunotherapy, biologic therapies, investigational agents are
             permitted as long as treatment was completed at least 12 months prior to the
             development of recurrent disease.

          8. Prior treatment with an Epidermal growth factor receptor tyrosine kinase inhibitors
             (EGFR-TKI).

          9. Major surgery within 4 weeks of the first dose of investigational product (IP).
             Procedures such as placement of vascular access, biopsy via mediastinoscopy or biopsy
             via video assisted thoracoscopic surgery are permitted.

         10. Radiotherapy treatment to more than 30% of the bone marrow or( with a wide field of
             radiation within 4 weeks of the first dose of investigational product (IP).

         11. History of hypersensitivity to active or inactive excipients of investigational
             product (IP) or drugs with a similar chemical structure or class to investigational
             product (IP).