Purpose of review: A major recent clinical research focus for glioblastoma has been the therapeutic evaluation of antiangiogenic agents. Several vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitors and a soluble decoy VEGF receptor have demonstrated nominal benefit among patients. In contrast, bevacizumab, a humanized VEGF monoclonal antibody, exhibits evidence of apparent antitumor benefit, although these data remain controversial. In this review, we summarize how results of clinical trials evaluating bevacizumab to date influence the future of this therapeutic for recurrent and newly diagnosed glioblastoma patients.
Recent findings: Recently reported, placebo-controlled phase III studies demonstrate a meaningful progression-free survival increment, but no overall survival benefit among newly diagnosed patients treated with bevacizumab. For unclear reasons, quality-of-life surveys from these studies revealed divergent results. Among recurrent patients, uncontrolled trials demonstrate improved overall radiographic response and progression-free survival rates, although the impact of bevacizumab on overall survival remains to be defined by an ongoing randomized phase III trial.
Summary: The role of bevacizumab for glioblastoma remains uncertain but will likely be strongly influenced by results of a randomized phase III study among recurrent patients as well as further investigation of gene expression biomarker profiles to identify newly diagnosed patients more likely to derive survival benefit.