Sequencing of ALK Inhibitors in ALK+ Non-Small Cell Lung Cancer.

OPINION STATEMENT: Major therapeutic advances have occurred over the last several years in the management of advanced ALK+ NSCLC patients. Crizotinib was the first agent approved for the management of ALK+ NSCLC patients after it demonstrated significantly greater clinical benefit compared to chemotherapy. Several next generation ALK inhibitors have demonstrated clinical benefit in patients with crizotinib refractory NSCLC patients including in the CNS. Based on available data, therapy with a next generation ALK inhibitor can be initiated following therapy with crizotinib without any assessment of the molecular mechanisms of resistance. The appropriate therapy for patients with progressive disease following two ALK inhibitors is not well defined. In patients with an ALK-resistant mutation in their tumor, an ALK inhibitor with activity against the mutation would be the most appropriate therapy. In others, chemotherapy and PD-1 directed agents can be considered. Clinical data suggests that ALK+ patients are less likely to benefit from PD-1 directed agents and therefore chemotherapy should be considered prior to these agents for the management of ALK+ NSCLC patients.