 Approximately 160 patients diagnosed with ALK-positive metastatic NSCLC according to the 7th edition of the AJCC American Joint Committee on Cancer Cancer Staging Manual and active lesions in the brain andor diagnosed with leptomeningeal carcinomatosis will be included in the study, approximately 40 patients in Arm 1 and Arm 2, approximately 30 patients in Arms 3 and Arm 4, and approximately 20 patients in Arm 5. Additional patients may be enrolled in Arm 4 to achieve approximately 60 patients in Arms 3 and 4 together i.e. ALKi naïve patients, if enrollment rate in Arm 3 is slow. 