Systematic review of sequencing of ALK inhibitors in ALK-positive non-small-cell lung cancer

The objective of this study was to understand outcomes of patients treated with ALK inhibitors, especially when ALK inhibitors are followed by other ALK inhibitors. A systematic literature review was conducted in PubMed, Embase, and Cochrane through July 17, 2017. Conference abstracts (three meetings in past 2 years) also were searched. Of 504 unique publications, 80 met inclusion criteria (47 clinical trials, 33 observational studies). Observational studies have the potential to provide information for ALK inhibitors used sequentially. Ten observational studies reported median overall survival of crizotinib-led sequences ranging from 30.3 to 63.75 months from initiation of crizotinib; 49.4–89.6 months from metastatic non-small-cell lung cancer diagnosis; and 15.5–22.0 months from initiation of the second-generation ALK inhibitor after initial crizotinib. Sequencing of ALK inhibitors may benefit patients progressing on initial ALK inhibitors.