Thema: News: Biomarkers to Predict Response to EGFR-Inhibitors
News: Biomarkers to Predict Response to EGFR-Inhibitors
Katja[a]
12.10.2005 21:19:00
Cell Cycle. 2005 Oct 17;4(10)
Biomarkers to Predict Response to Epidermal Growth Factor Receptor Inhibitors.
Haas-Kogan DA, Prados MD, Lamborn KR, Tihan T, Berger MS, Stokoe D.
Department of Radiation Oncology, Departments of Neurosurgery and Brain Tumor Research Center, University of California-San Francisco, San Francisco, California, USA.
Epidermal growth factor receptors (EGFRs) are amplified and overexpressed in many different human cancers, a phenomenon generally associated with poor prognosis. Inhibitors of the tyrosine kinase activity associated with this receptor have been approved for the treatment of chemotherapy-refractory nonsmall cell lung cancer, and are in clinical trials for additional tumor types. While these inhibitors, gefitinib and erlotinib, display limited response rates when assessed in cohorts that include all patients, there are subgroups, defined by patient and tumor characteristics, that preferentially respond to these agents. We recently performed an analysis of tumors obtained from a Phase I trial of erlotinib in patients with glioblastoma multiforme (GBM), the most common malignant brain tumor in adults. We showed that patients whose tumors exhibited overexpression and amplification of EGFR responded better than patients who had normal levels of this gene and protein. We also demonstrated that the phosphorylation state of PKB/Akt was an important determinant for response, with low phospho-PKB/Akt levels predicting good response to erlotinib. We discuss these findings in the context of recent molecular analyses of the placebo-controlled Phase III trials that led to approval of EGFR inhibitors. These data underscore the importance of placebo-controlled trials to distinguish between prognostic indicators of disease progression more generally and predictive markers of response to therapy. Ultimately the goal of these studies is to allow selection of patients who will preferentially respond to EGFR inhibitors.
Biomarkers to Predict Response to Epidermal Growth Factor Receptor Inhibitors.
Haas-Kogan DA, Prados MD, Lamborn KR, Tihan T, Berger MS, Stokoe D.
Department of Radiation Oncology, Departments of Neurosurgery and Brain Tumor Research Center, University of California-San Francisco, San Francisco, California, USA.
Epidermal growth factor receptors (EGFRs) are amplified and overexpressed in many different human cancers, a phenomenon generally associated with poor prognosis. Inhibitors of the tyrosine kinase activity associated with this receptor have been approved for the treatment of chemotherapy-refractory nonsmall cell lung cancer, and are in clinical trials for additional tumor types. While these inhibitors, gefitinib and erlotinib, display limited response rates when assessed in cohorts that include all patients, there are subgroups, defined by patient and tumor characteristics, that preferentially respond to these agents. We recently performed an analysis of tumors obtained from a Phase I trial of erlotinib in patients with glioblastoma multiforme (GBM), the most common malignant brain tumor in adults. We showed that patients whose tumors exhibited overexpression and amplification of EGFR responded better than patients who had normal levels of this gene and protein. We also demonstrated that the phosphorylation state of PKB/Akt was an important determinant for response, with low phospho-PKB/Akt levels predicting good response to erlotinib. We discuss these findings in the context of recent molecular analyses of the placebo-controlled Phase III trials that led to approval of EGFR inhibitors. These data underscore the importance of placebo-controlled trials to distinguish between prognostic indicators of disease progression more generally and predictive markers of response to therapy. Ultimately the goal of these studies is to allow selection of patients who will preferentially respond to EGFR inhibitors.
Katja[a]
