Background: Single-agent durvalumab is being evaluated in patients with advanced squamous and non-squamous NSCLC in an ongoing Phase 1/2 study (NCT01693562). Here we present updated survival and safety data in NSCLC patients. Methods: Treatment-naïve (1L) and previously treated (2L or 3L+) stage IIIB/IV NSCLC patients received durvalumab 10 mg/kg Q2W for up to 12 months. Patients were stratified by tumor PD-L1 expression (Ventana PD-L1 [SP263] Assay [PD-L1 high: ≥25% of tumor cells with membrane staining]), treatment line, and histology. Results: As of 05 September 2017, 304 NSCLC patients received durvalumab monotherapy. Median duration of follow-up was 35.6 (0.3–50.9) months. Investigator-assessed ORR ranged between 23.2% and 30.0% among PD-L1 high patients, and between 3.6% and 8.3% among PD-L1 low/negative patients. Median PFS and median OS were longer in PD-L1 high vs PD-L1 low/negative patients (Table). Any-grade treatment-related AEs (TRAEs) were reported in 57.2% of pts (including fatigue, 17.4%, decreased appetite, 9.2%, diarrhea, 8.9%); in 10.2% of pts these were Grade 3 or 4. TRAEs resulting in treatment discontinuation were reported in 17 patients (5.6%); 1 patient had a Grade 5 TRAE (pneumonia). Conclusions: In this ongoing phase 1 study, OS and safety profile appear encouraging in treatment-naïve and previously treated NSCLC patients, particularly among PD-L1 high patients. Further investigation regarding PD-L1 expression for selection of patients who most likely benefit from durvalumab is needed. Clinical trial information: NCT01693562