Based on published results regarding the potential therapeutic benefit of adult and pediatric high grade glioma patients receiving either the histone deacetylase (HDAC) inhibitor valproic acid (VPA; Barker et al. 2013; Wolff et al. 2008, 2011; Felix et al. 2011; Su et al. 2011; Rokes et al. 2010; Masoudi et al. 2008; Guthrie et al. 2013; Weller et al. 2011) or the autophagy inhibitor chloroquine (CQ; Briceño et al. 2003, 2007; Sotelo et al. 2006) in addition to radiochemotherapy, the present trial is aimed to investigate if the addition of VPA or CQ to radiochemo- and maintenance therapy with temozolomide (Stupp et al. 2005; Cohen et al. 2011a, b) provides a survival advantage in comparison to each other and also in comparison to radiochemo- and maintenance therapy with temozolomide alone. Differences in therapeutic efficiencies between VPA and CQ will be evaluated in a randomized fashion followed by comparison with a historical patient control from the previous trial HIT-HGG-2007 with temozolomide radiochemo- and maintenance therapy alone. Besides therapeutic efficiencies as indicated by event-free survival (EFS) and overall survival (OS) treatment-related toxicities will also be analysed.