ALK fusion variant 3a/b, concomitant mutations, and high PD-L1 expression were associated with unfavorable clinical response to second-generation ALK TKIs in patients with advanced ALK-rearranged non-small cell lung cancer (GASTO 1061)

•Second-generation ALK TKIs have been the standard treatment in advanced ALK-rearranged NSCLC, but clinical responses vary widely.•High PD-L1 expression was associated with ALK fusion variant 3a/b and concomitant mutations in ALK-rearranged NSCLC.•ALK fusion variant 3a/b, concomitant mutations, and high PD-L1 expression were associated with unfavorable clinical response to second-generation ALK TKIs in ALK-rearranged NSCLC.