Clinical Outcome of Crizotinib in ROS1-Positive Metastatic Non-small Cell Lung Cancer: A Single-Institution Experience From a Tertiary Care Centre in Northern India

IntroductionCrizotinib is a selective adenosine triphosphate (ATP)-competitive small-molecule ROS proto-oncogene 1 (ROS1) inhibitor with high clinical efficacy.In the current study, we attempted to add to the real-world experience of crizotinib, its efficacy, safety data and clinical characteristics of patients with ROS1-positive non-small cell lung cancer (NSCLC). MethodsThirty patients with ROS1-rearranged metastatic NSCLC fulfilling the inclusion and exclusion criteria were retrospectively analysed at Rajiv Gandhi Cancer Institute and Research Centre, New Delhi.Inclusion criteria included patients aged >18 years, Eastern Cooperative Oncology Group Performance Status Scale (ECOG PS 1-3), metastatic, histologically confirmed NSCLC with measurable disease and ROS1 rearrangement.Crizotinib was administered orally at 250 mg twice daily until disease progression, unacceptable toxicity, study withdrawal or death.The primary efficacy endpoint was the overall response rate.The secondary endpoints included progression-free survival (PFS), overall survival (OS) and probability of survival at 12, 24, 36 and 60 months.Kaplan-Meier curves were generated to depict PFS (first-line/second-line setting) and OS.The study analysed the impact of various clinical and demographic covariates on OS and PFS using the Cox proportional hazards regression model. ResultsThirty patients received ROS1 inhibitors as first-line (n = 23, 76.7%) or second-line treatment (n = 7, 23.3%).Around 70% (21/30) of patients had partial response, and 20% (06/30) had stable disease.Overall, median PFS was 20 months.Median PFS was 16 months and 34 months in the first-line and second-line treatments, respectively.Median OS was 47 months, with three-year and five-year survival probabilities of 75% and 45.3%, respectively. ConclusionsOur study represents the largest single-institution patient cohort of ROS1-positive NSCLC patients treated with crizotinib from North India.Long-term OS and a favourable adverse-event profile support the continued use of crizotinib in the treatment of ROS1-rearranged NSCLC.