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.
Circulating tumor DNA can be used to monitor the treatment effect and identify developing resistance mutations during ALK directed TKI treatment.