TAGRISSO (Osimertinib) in NSCLC Patients in Whom T790 Mutations Are Detected by Liquid Biopsy

A cycle of study treatment is defined as 28 days. Each subject will continue the study drug(Osimertinib) until disease progression or manifestation of unacceptable toxicity during the study period. The study drug will be administered orally as one 80 mg tablet once a day. The initial dose of the study drug 80 mg daily can be reduced to 40 mg once daily.