ES-2 Phase 3 TRIDENT Trial: Radiation and Temozolomide with or without Tumor Treating Fields in newly diagnosed glioblastoma

Background: Tumor treating fields (TTFields) is a non-invasive, regional antimitotic treatment approved as a standard-of-care for glioblastoma. In the EF-14 Phase 3 trial, TTFields (200 kHz) plus temozolomide (TMZ) significantly increased survival of patients with newly diagnosed GBM(ndGBM) without increasing systemic toxicity. TTFields-related AEs were mainly skin AEs. In preclinical models, TTFields increase the therapeutic effects of radiation therapy (RT). A pilot study showed that TTFields concomitant with RT and TMZ is well tolerated. The benefit of concomitant TTFields with RT and TMZ will be tested in the TRIDENT trial. Methods: TRIDENT is an international phase III randomized trial comparing standard RT/TMZ vs the triple combination of RT/TMZ with concomitant TTFields. RT is delivered through the TTFields arrays. Patients in both arms will receive maintenance TTFields/TMZ. TTFields (200 kHz) will be delivered over18 hours/day using Optune. Patients will continue TTFields treatment until second recurrence. Patients with pathologically confirmed ndGBM, over 18 years old, KPS over 70, either sex, post-surgery or biopsy, and amenable for RT/TMZ therapy will be stratified by extent of resection and MGMT promoter methylation status. The primary endpoint is overall survival (OS). Secondary end points: progression free survival (PFS; RANO), 1- and 2-year survival rates, overall radiological response (ORR; RANO), progression-free survival (PFS2, PFS6, PFS12); severity and frequency of AEs (CTCAE V5.0); pathological changes in resected GBM tumors post treatment; quality of life (EORTC QLQ-C30); and correlation of OS to TTFields compliance. The hypothesis is that concomitant TTFields/RT/TMZ will significantly improve OS versus RT/TMZ. Sample size (N=950; 475/arm) will detect a HR lower than 0.8 with 5% type I error. Survival will be measured from the time of randomization until date of death. At the time of analysis, patients lost to follow-up or still on protocol follow-up will be censored at the last date known to be alive.