9092 Background: Alectinib is a standard of care option in advanced ALK-rearranged (ALK+) non-small cell lung cancer (NSCLC) patients (pts), with efficacy established by phase 3 trials, in first-line and beyond. There are few efficacy data in unselected populations. Methods: The objective of this study was to evaluate the efficacy of alectinib in real-world setting. All ALK+ advanced NSCLC pts initiating alectinib, between December 13, 2017 (date of access in France) and June 27, 2020, whatever the line, were included in explore ALK study. Patient characteristics, alectinib duration of treatment (DOT), progression-free survival assessed locally (rwPFS), overall survival (OS) according to the prescription line of alectinib, the presence of brain metastases at alectinib initiation, response rate and tolerance were collected from the medical files. Results: The analysis included 223 pts: 46.2% were men, 84.7% had no smoking history or were former smokers, median age was 59 (22-101) years and 95% were adenocarcinomas. Alectinib was initiated as first-line treatment in 119 pts, with a PS of 0/1/>1 in 42%/31%/27% of cases, a median number of metastatic sites of 2 (cerebral, hepatic, bone in 33%, 24% and 32% of cases). In first-line setting, after a median follow-up of 33.7 months (95%CI, 32.2-37.5), the median of rwPFS and DOT were 28.1 (95%CI, 20.7-40.4) and 26.9 (95%CI, 20.2-31.3) months, respectively. The median OS was not reach (NR), the 3-year OS rate was 72.1%. The rwPFS was not significantly different depending on whether or not the patient has brain metastases, 28.1 (95% CI, 14.5-NR) and 30.5 (85% CI, 18.9-40.4) months, respectively. The best response was complete (CR), partial (PR) and stable (SD) in 21%, 58% and 17%. The cerebral response, evaluable in 30/39 of the pts, was CR, PR and SD in 26%, 46% and 23% respectively; 33% of pts had a grade 3 adverse event, resulting in a temporary interruption of treatment in 7.6% of cases and a permanent discontinuation in 5.9% of cases. At the time of progression, 48.1% of pts had a new biopsy (66% of tissue biopsy). Efficacy data for alectinib prescribed as second line and above are summarized in the table. Conclusions: In this large real-world, cohort of unselected advanced ALK+ NSCLC pts, alectinib initiated in 1st-line or beyond provides similar efficacy and safety results as obtained in phase III clinical trials. [Table: see text]