Failures in preclinical and clinical trials of c-Met inhibitors: evaluation of pathway activity as a promising selection criterion
Metrics: PDF 1067 views | Full Text 1047 views | ?
Veronica S. Hughes1 and Dietmar W. Siemann1
1University of Florida, Department of Radiation Oncology, UF Health Cancer Center, Gainesville, FL 32608, USA
Dietmar W. Siemann, email: email@example.com
Keywords: cancer; c-Met; small molecule inhibitor; microenvironment; HGF
Received: November 01, 2018 Accepted: December 20, 2018 Published: January 04, 2019
C-Met is a frequently overexpressed or amplified receptor tyrosine kinase involved in metastatic-related functions, including migration, invasion, cell survival, and angiogenesis. Because of its role in cancer progression and metastasis, many inhibitors have been developed to target this pathway. Unfortunately, most c-Met inhibitor clinical trials have failed to show significant improvement in survival of cancer patients. In these trials tumor type, protein overexpression, or gene amplification are the primary selection criteria for patient inclusion. Our data show that none of these criteria are associated with c-Met pathway activation. Hence, it is conceivable that the majority of c-Met inhibitor clinical trial failures are the consequence of a lack of appropriate patient selection. Further complicating matters, c-Met inhibitors are routinely tested in preclinical studies in the presence of high levels of exogenous Hepatocyte Growth Factor (HGF), its activating ligand. In our studies, several tumor cell lines showed sensitivity to a c-Met inhibitor at high HGF concentrations (50 ng/mL). However, when the tumor lines were tested at HGF levels typically detected in human serum (0.4 to 0.8 ng/mL), inhibitor activity was lost. Thus testing c-Met inhibitors at non-physiological concentrations of HGF may lead to incorrect predictions of drug efficacy in vivo.
All site content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 License.