International Cooperative Phase III Trial of the HIT-HGG Study Group (HIT-HGG-2013)

The HIT-HGG-2013 trial offers an innovative high-quality diagnostics and science program for children and adolescents \>3 years, suffering from one of the following types of high grade gliomas: 1. glioblastoma WHO grade IV (GBM) 2. diffuse midlineglioma histone 3 K27M mutated WHO grade IV (DMG) 3. anaplastic astrocytoma WHO grade III (AA) 4. diffuse intrinsic pontine glioma (DIPG) 5. gliomatosis cerebri (GC) For 1.-3. diagnosis has to be confirmed by neuropathological survey, for 4. and 5. diagnosis has to be confirmed by neuroradiological survey. In addition to standard treatment (radiotherapy and temozolomide chemotherapy) the effect of valproic acid which is traditionally used for treatment of seizure disorder, will be investigated. The aim of the trial will be to investigate whether this drug may increase the effects of radio- and chemotherapy, resulting in a better survival of the treated patients. Scientific studies provided evidence for anti-tumoral effects of valproic acid: the drug seems to be a so-called histondeacetylase inhibitor (HDAC inhibitor), controlling important genetic processes of tumor growth. Studies in cell culture, animals and first clinical trials in adults as well provided evidence for efficacy of valproic acid in the treatment of glioblastoma. Due to this we hope children and adolescents suffering from GBM, DMG, AA, DIPG und GC will benefit from the treatment, too. The aim of the HIT-HGG-2013 trial will be to compare the effects of Valproic acid with data of the HIT-HGG-2007 trial (children and adolescents with same diseases, only treated with simultaneous temozolomide radiochemotherapy). In the present study, it was originally planned to investigate the therapeutic efficiency and safety of valproic acid and the autophagy inhibitor chloroquine, both in addition to temozolomide therapy. Since distribution of Resochin junior (chloroquine phosphate) was terminated, recruitment of new patients was stopped on August 8, 2019. For continuat