Approximately 100 patients with locally advanced or metastatic NSCLC which carry ALK -rearrangement will be enrolled in the study. The first 15 patients to be enrolled in the study will have PK sampling over 120-hour during the 5-day PK run-in period following a single oral dose at 750 mg. After the PK run-in period, the treatment period will start in which LDK378 will be given starting on Cycle 1 Day 1 in a continuous daily oral dosing in 28-day cycles. Separated from these 15 patients, the rest of the enrolled patients will receive LDK378 treatment at 750 mg QD on Cycle 1 Day 1.