Abstract
BACKGROUND: KRAS mutations are identified in approximately 25% of non-small cell lung cancer (NSCLC) cases and are associated with resistance to currently available targeted therapies. The MET oncogene may be implicated in malignant progression of KRAS-mutant tumors. In a pre-specified subset analysis of KRAS mutant cancers in an earlier phase 2 study of erlotinib plus the oral MET inhibitor tivantinib, combination therapy was associated with substantial clinical benefit compared to erlotinib alone (progression-free survival [PFS] HR 0.18; P < 0.01). The current study was conducted to evaluate this combination further in KRAS mutant non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Previously treated patients with advanced KRAS mutant NSCLC were randomized to receive either oral tivantinib (360 mg twice daily) plus erlotinib (150 mg daily) (ET) or single-agent chemotherapy (investigator's choice of pemetrexed, docetaxel, or gemcitabine) (C). The primary endpoint was PFS. At progression, crossover from C to ET was permitted. RESULTS: Ninety-six patients were randomly assigned to ET (n = 51) or to C (n = 45). Median PFS was 1.7 months (mos) for ET and 4.3 mos for C (HR 1.19; 95% CI, 0.71-1.97; P = 0.50). There was no difference in overall survival (HR 1.20; 95% CI, 0.76-1.88; P = 0.44). There were 4 partial responses in the C arm, and none in the ET arm. Overall, adverse events occurred more frequently in the C arm, with more cytopenias, nausea, fatigue, and alopecia. Dermatologic toxicities were more common in the ET arm. CONCLUSION: In previously treated patients with advanced KRAS mutant NSCLC, the combination of the MET inhibitor tivantinib and erlotinib is not superior to conventional single-agent chemotherapy.