A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study of Optune® (TTFields, 200 kHz) Concomitant With Maintenance Temozolomide and Pembrolizumab Versus Optune® Concomitant With Maintenance Temozolomide and Placebo for the Treatment of Newly Diagnosed Glioblastoma (EF-41/KEYNOTE D58).