ALK Resistance Mutations and Efficacy of Lorlatinib in Advanced Anaplastic Lymphoma Kinase-Positive Non–Small-Cell Lung Cancer

In patients who have failed 1 or more second-generation ALK TKIs, lorlatinib shows greater efficacy in patients with ALK mutations compared with patients without ALK mutations. Tumor genotyping for ALK mutations after failure of a second-generation TKI may identify patients who are more likely to derive clinical benefit from lorlatinib.