Molecular correlates of response to capmatinib in advanced non-small-cell lung cancer: clinical and biomarker results from a phase I trial

Background: Dysregulation of receptor tyrosine kinase MET by various mechanisms occurs in 3%-4% of non-small-cell lung cancer (NSCLC) and is associated with unfavorable prognosis. While MET is a validated drug target in lung cancer, the best biomarker strategy for the enrichment of a susceptible patient population still remains to be defined. Towards this end we analyze here primary data from a phase I dose expansion study of the MET inhibitor capmatinib in patients with advanced MET-dysregulated NSCLC. Patients and methods: Eligible patients [>= 18 years; Eastern Cooperative Oncology Group (ECOG) performance status <= 2] with MET-dysregulated advanced NSCLC, defined as either (i) MET status by immunohistochemistry (MET IHC) 2+ or 3 or H-score >= 150, or MET/centromere ratio >= 2.0 or gene copy number (GCN) >= 5, or (ii) epidermal growth factor receptor wild-type (EGFRwt) and centrally assessed MET IHC 3+, received capmatinib at the recommended dose of 400 mg (tablets) or 600 mg (capsules) b.i.d. The primary objective was to determine safety and tolerability; the key secondary objective was to explore antitumor activity. The exploratory end point was the correlation of clinical activity with different biomarker formats. Results: Of 55 patients with advanced MET-dysregulated NSCLC, 40/55 (73%) had received two or more prior systemic therapies. All patients discontinued treatment, primarily due to disease progression (69.1%). The median treatment duration was 10.4 weeks. The overall response rate per RECIST was 20% (95% confidence interval, 10.4-33.0). In patients with MET GCN >= 6 (n = 15), the overall response rate by both the investigator and central assessments was 47%. The median progression-free survival per investigator for patients with MET GCN >6 was 9.3 months (95% confidence interval, 3.8-11.9). Tumor responses were observed in all four patients with METex14. The most common toxicities were nausea (42%), peripheral edema (33%), and vomiting (31%). Conclusions: MET GCN >= 6 and/or METex14 are suited to predict clinical activity of capmatinib in patients with NSCLC (NCT01324479).