e20631 Background: To date, there are no robust studies in real world practice describing the use of IO (immuno-oncology) treatments in advanced/metastatic (adv/m) NSCLC. The available evidence in Europe is limited to observational studies of small size. This study aims to understand the impact of IO in adv/mNSCLC and study the profile of patients currently receiving these treatments. Methods: 20,157 cases of 1st and 2nd line adv/mNSCLC patients between October 2016 and September 2018 in EU5 (France, Germany, Spain, Italy, UK) were identified within Oncology Dynamics, an IQVIA oncology syndicated cross sectional survey collecting anonymized patient-level data. Patient profile was described, and two groups were created to assess differences in the use of IO treatments (nivolumab, pembrolizumab, atezolizumab, ipilimumab, durvalumab) across 2 time periods: #1 October 2016 - September 2017 (n = 9,310); #2 October 2017 - September 2018 (n = 10,847). Results: IO treatments increased 15% in 1st line adv/mNSCLC (13% in non-squamous and 23% in squamous histology) and 11% in 2nd line across periods; reaching treatment shares of 20.3% and 67.9% in 1st line and 2nd line in Period 2. Within IO-treated patients, 9.5% in 1st line and 13.6% in 2nd line had ECOG ≥2, and 27% were > 71 years old. The use of IO in 1st line patients without mutations (EGFR/ALK/ROS1/BRAF) increased by 24%, while standard chemotherapy decreased by 21%. Conclusions: IO treatments had a rapid adoption in Europe last year, influenced by its approval in 1st line adv/mNSCLC and by clinical guidelines recommendations. Ongoing clinical trials may suggest a growing trend in the future that could potentially impact in healthcare systems. In addition, real world patients treated with IO are older and have a worse performance status than those widely included in clinical trials. An evaluation of these results sheds light into IO treatments in NSCLC and may contribute to the design of real-world studies to generate new evidence and optimize the use of these class of drugs in clinical practice.[Table: see text]