Background: Brigatinib is a next-generation tyrosine kinase inhibitor targeting ALK and ROS1. Crizotinib is the first drug approved for the treatment of ROS1 fusion-positive NSCLC. Standard treatment for crizotinib-resistant ROS1 positive NSCLC is not established. Barossa is a multicenter, phase II basket, study of brigatinib in patients with ROS1 positive solid tumors. This study is composed of three cohorts. ROS1 inhibitor-naïve ROS1 positive NSCLC patients were enrolled in the cohort 1, and ROS1 positive NSCLC patients previously treated with crizotinib were enrolled in the cohort 2. Patients with ROS 1 positive solid tumors other than NSCLC were enrolled in the cohort 3. This time we report the cohort 2 results. Methods: Patients with advanced, previously treated with crizotinib, ROS1 positive NSCLC received brigatinib at a dose of 180 mg once daily with a 7-day lead-in period at 90 mg. The primary end point was objective response rate (ORR; RECIST 1.1) by independent review. Key secondary endpoint was PFS, OS, and safety. The sample size was set at 19 patients, with a one-sided alpha of 0.05, beta of 0.2, and threshold and expected values for primary endpoint of 20% and 50%, respectively. Results: From July 2019 and Jan 2020, 19 patients were enrolled from 9 institutions. Baseline characteristics as follows: median age (range): 60 (31-75) years; women, n = 10 (53%); ECOG PS of 0 to 1, n = 18 (95%); never smoker, n = 11 (58%); tumor histopathological type: adenocarcinoma, n = 18 (95%). Five and 6 patients achieved PR and SD, respectively at data cutoff date of 30 Oct 2020. The ORR was 26.3% (90%CI, 11.0-47.6), and the disease control rate was 57.9% (95%CI, 33.5-79.7). The median duration of follow-up for PFS was 12.0 months. The median PFS was 7.3 months (95% CI, 1.3-9.3), and the 1-year PFS rate was 26.9% (95%CI, 9.2-48.6). Grade ≥3 TRAEs were CPK increased (21.1%), infection (5.3%), AST and/or ALT increased (5.3%), hypercalcemia (5.3%), anorexia (5.3%), hypoxia (5.3%), erythema (5.3%), hypertension (5.3%). Pneumonitis was observed in one patient (5.3%, Grade 2). No treatment-related death was observed. Conclusions: Brigatinib has modest activity for ROS1 positive NSCLC patients previously treated with crizotinib. The safety profile of brigatinib was consistent with previous studies. Enrollment of the cohort 1 for ROS1 inhibitor-naïve NSCLC patients is ongoing, and the data will be presented at a future congress. Clinical trial information: JapicCTI-194851.