MEDI4736 (Anti PD-L1) Combined With Gefitinib in Subjects With Non-Small Cell Lung Cancer(NSCLC).

Key Inclusion Criteria: 1. Provision of signed and dated, written informed consent 2. Male or female aged 18 years and older. 3. Subjects must have a. In the escalation phase, locally advanced or metastatic NSCLC subjects who have either failed to respond or relapsed following any line of standard treatment, were unable to tolerate, or were not eligible for standard treatment b. In the expansion phase, histologically or cytologically confirmed locally advanced or metastatic NSCLC that is EGFR mutation positive, naïve to EGFR TKI therapy, and sensitive to EGFR TKIs therapy 4. a.For Escalation Phase: At least one lesion (measurable and/or non-measurable) b.For Expansion Phase: At least one measurable lesion. 5. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. * For Japan Escalation - the same as the global escalation I/E criteria except patients must be EGFR mutation positive Key Exclusion Criteria: 1. Any concurrent chemotherapy, immunotherapy, biologic, or hormonal therapy for cancer treatment. 2. Any investigational agent, chemotherapy, immunotherapy, biologic, hormonal within 28 days of the first dose of study treatment 3. Inadequate bone marrow reserve or organ function