Additional Relevant Details The ACT IV study is a randomized, double-blind, placebo controlled study of RINTEGA plus GM-CSF added to standard of care temozolomide in patients with newly diagnosed, surgically resected, EGFRvIII-positive glioblastoma. 745 patients were enrolled into ACT IV to reach the required 374 patients with minimal residual disease (assessed by central review) needed for analysis of the primary overall survival endpoint. All patients, including those with disease that exceed this threshold, will be included in a secondary analysis of overall survival as well as analyses of progression-free survival, safety and tolerability, and quality of life. The study design includes interim analyses conducted by an independent Data Safety and Monitoring Board (DSMB) at 50 and 75% of events (deaths). The first interim analysis occurred in June 2015, and the DSMB recommended continuation of the study as planned.