The standard of care for newly diagnosed glioblastoma includes surgery, involved-field radiotherapy, and concomitant and six cycles of maintenance temozolomide chemotherapy, however the prognosis remains dismal. Marizomib has been tested in patients with newly diagnosed and recurrent glioblastoma in phase I and phase II studies. In patients with recurrent glioblastoma, marizomib was administered as a single agent or in combination with bevacizumab (NCT02330562). Based on encouraging observations, a phase I/II trial of marizomib in combination with TMZ/RT –>TMZ in newly diagnosed glioblastoma has been launched (NCT02903069) which explores safety and tolerability of this triple combination and which shall help to determine the dose for further clinical trials in glioblastoma. In this context, given that marizomib has been established as a safe addition to the standard TMZ/RT –>TMZ, a phase III study is considered essential to establishing its impact on overall survival.