Updated project metadata. The present pre-clinicial study sought to evaluate the novel EGFR inhibitor WSD-0922. We employed flank and orthotopic patient derived xenograft (PDX) models to characterize WSD-0922 and compare its therapeutic efficacy to erlotinib, a potent EGFR inhibitor that failed to provide clinical benefit for GBM patients. We utilized phosphotyrosine mass spectrometry analyses to measure the impact of each drug on receptor activity and cellular signaling networks.