Several drugs have been tested, including epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (gefitinib and erlotinib), mammalian target of rapamycin (mTOR) inhibitors (temsirolimus and everolimus), and vascular endothelial growth factor receptor (VEGFR), protein kinase C-beta, and other angiogenesis pathways inhibitors (vatalanib, bevacizumab, and enzastaurin). Although preliminary efficacy results of most trials in recurrent disease have fallen short on expectations, substantial advances have been achieved by associated translational research.