Treatment Patterns and Clinical Outcomes Among Patients With ROS1-rearranged Non–small-cell Lung Cancer Progressing on Crizotinib

Background: ROS1 rearrangements define a subset of non–small-cell lung cancers (NSCLCs) that are susceptible to therapeutic ROS1 kinase inhibition. Despite the fact that most patients initially respond to the first-generation ROS1 tyrosine kinase inhibitor (TKI) crizotinib, relapse invariably occurs, and therapeutic options upon disease progression are limited. Patients and Methods: We conducted a multicenter study of patients with ROS1-rearranged NSCLC who progressed on ROS1 TKIs and examined the clinical outcomes based on the post-progression treatment approaches. Results: Among 29 patients with ROS1-rearrangement who received at least 1 ROS1 inhibitor, the median age was 51 years (range, 30-80 years), 70.8% of patients were female, and 68.9% were never-smokers. Upon progression to the first TKI, 11 patients (37.9%) received treatment with TKIs beyond progression. The median second progression-free survival to TKIs in patents treated beyond progression was 5.5 months (95% confidence interval [CI], 4.1-9.1 months), whereas the post-progression survival was 21.0 months (95% CI, 5.5 months-not reached [NR]). Eleven (37.9%) patients received a sequential treatment with lorlatinib ROS1 TKIs following a first generation ROS1 TKI. The overall response rate, median progression-free survival, and median overall survival (OS) to next-generation TKIs were 41.7% (95% CI, 15.2%-72.3%), 12.7 months (95% CI, 8.5 months-NR), and 17.0 months (95% CI, 15.8 months-NR), respectively. Patients treated with sequential ROS1 TKIs had a significantly longer median OS compared with those who were not (NR vs. 16.1 months; hazard ratio, 0.26; 95% CI, 0.10-0.78; P = .017). Conclusion: In this study, we reported that a subset of patients with ROS1-rearranged NSCLC may benefit from treatment with TKIs beyond progression and that sequential treatment with crizotinib followed by lorlatinib is associated with improved OS in patients with ROS1-rearranged NSCLC