Monitoring Alectinib Treatment by Detection of ALK Translocations in Serial Blood Samples From Non-Small Cell Lung Cancer Patients

The purpose and objectives of the non-interventional study with primary data collection is * To determine if monitoring the amount of translocated DNA in the blood reflects alectinib treatment effect. * To assess the presence and type of resistance mutations using ctDNA at the time patients experience clinical progression on alectinib. * To investigate if the resistance mutations identified at clinical progression could have been identified in blood samples taken before clinically evident progression.