A phase II trial of a selective c-Met inhibitor tivantinib (ARQ 197) monotherapy as a second- or third-line therapy in the patients with metastatic gastric cancer

Background Tivantinib is a selective, non-ATP competitive, small-molecule inhibitor of c-Met and is under development in several cancers including non-small cell lung and hepatocellular carcinoma. Activation of c-Met has been frequently found in metastatic gastric cancer (MGC) and is associated with poor prognosis. In this single-arm study, we evaluated the efficacy of tivantinib monotherapy in Asian patients with previously treated MGC. This is the first clinical report from the trials evaluating the efficacy of a selective c-Met inhibitor for MGC. Patients and methods Eligibility criteria included: MGC with at least one measurable lesion; 1 or 2 prior chemotherapy regimens; and ECOG PS 0 or 1. Tivantinib was daily administered orally. The primary endpoint was the disease control rate (DCR). Pre-treatment tumor tissue was collected to evaluate the biomarkers related to efficacy. Results Thirty patients, including 12 patients with prior gastrectomy, received tivantinib: median age 62.5 years; ECOG PS 0/1 (8/22); 1/2 prior regimen (16/14). No objective response was observed, and DCR was 36.7 %. Median progression-free survival was 43 days (95 % CI: 29.0-92.0). Grade 3 or 4 adverse events occurred in 13 patients (43.3 %), in whom neutropenia (N = 4) and anemia (N = 4) were recognized as drug-related. c-Met gene amplification was observed in 2 patients (6.9 %). No obvious relationship was identified between efficacy and biomarkers including gene amplification of c-Met, expression of c-Met, p-Met and HGF. Conclusion Tivantinib as a monotherapy showed a modest efficacy in previously treated MGC, and further studies taking account of predictive biomarkers and/or combination with other chemotherapy may be needed in MGC.