Crizotinib presented with promising efficacy but for concomitant mutation in next-generation sequencing-identified ROS1-rearranged non-small-cell lung cancer

Introduction: Data of standard tyrosine kinase inhibitor (TKI) treatment outcome in next-generation sequencing (NGS)-identified ROS1-rearranged non-small-cell lung cancer (NSCLC) were rare. Thus, it is practical and necessary to evaluate the efficacy and influential factors of crizotinib in real-world practice. Patients and methods: A total of 1,466 NSCLC patients with positive targeted NGS test results from September 2015 to January 2018 were enrolled in this real-world retrospective study. Twenty-two patients had ROS1 rearrangement detected by NGS. The efficacy and safety of crizotinib were evaluated. Subgroups of concomitant mutations, brain metastasis, and fusion variants were also analyzed. Results: Among all the patients, the occurrence rate of ROS1 rearrangement was 1.5% (22 of 1,466). Ten ROS1 fusion partners were detected, and the most common variant was CD74, which accounted for 50% (11 of 22). Five patients were found to carry dual ROS1 fusion partners, and 23% (5 of 22) of patients were detected with concomitant mutations, including TP53&PIK3CA&mTOR mutation, TP53&CDKN2A mutation, TP53&BRCA2 mutation, ALK missense mutation (p.R311H), and MET amplification. Among 22 patients with ROS1-rearranged NSCLC, 20 patients were diagnosed at stage IV, and 19 patients received crizotinib treatment. The average follow-up period was 16 months. The overall response rate (ORR) of crizotinib in unselected crizotinib-treated patients was 89%, and the median progression-free survival time (mPFS) was 13.6 months. It was shown that NSCLC patients with exclusive ROS1 rearrangement had a longer PFS than those carrying concomitant mutations (15.5 vs 8.5 months, P=0.0213). There were no newly occurring intolerant adverse events in this study. Conclusion: Crizotinib is highly effective in NGS-identified ROS1-rearranged advanced NSCLC in real-word clinical practice, and the data are consistent with previous clinical trials applying fluorescence in situ hybridization/real-time PCR for ROS1 companion diagnosis. Concomitant mutations may not be rare and may deteriorate the PFS of crizotinib in patients with ROS1-rearranged NSCLC.