The search for novel therapeutic strategies in the treatment of recurrent glioblastoma multiforme.

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor with ≤10% patients surviving 5 years from the time of diagnosis. After tumor progression on frontline therapy with concomitant chemoradiotherapy followed by consolidation temozolomide there are few effective treatment options. Bevacizumab and nitrosureas are the most commonly used systemic options in this instance but no overall survival benefit has been demonstrated. In this review we outline the major avenues of research for treatment of recurrent GBM including anti-angiogenic, signaling pathway blockade and immunotherapy approaches. Results of recent trials as well as pertinent ongoing studies are discussed. Enrollment of patients to clinical trials as well as incorporation of correlative translational science studies to identify predictive biomarkers of treatment response will be key to improving outcomes in this devastating disease.