There are 2 parts to this study:~Part 1 (dose escalation) and Part 2 (dose expansion). The main purpose of Part 1 is Dose-Escalation. Dose-Escalation means that different dose levels will be tested at different times during the study to find the best dose level that is safe and well tolerated in participants. In this study investigators will determine the best dose of Vorinostat that can be given with pembrolizumab, chemotherapy and radiotherapy. The dose of temozolomide and radiotherapy will be the same as standard treatment.~Part 2 (Dose Expansion), all participants will receive the same dose of vorinostat with pembrolizumab, chemotherapy and radiotherapy.~Maintenance Phase: During the maintenance phase, participants will receive Temozolomide (for the first 6 months), vorinostat (for 12 months), and pembrolizumab (for 12 months).
The purpose of this research study is to test the safety and tolerability of the combination treatment of the investigational drugs vorinostat and pembrolizumab, in combination with chemotherapy (temozolomide), and radiotherapy. The U.S. Food and Drug Administration (FDA) has approved pembrolizumab for use to treat a deadly skin cancer called melanoma and lung cancer and vorinostat to treat some forms of blood and lymph node cancers. However, both vorinostat and pembrolizumab are considered investigational drugs in this study because they are not approved for treatment of glioblastoma.