BACKGROUND: Addition of temozolomide (TMZ) to radiotherapy (RT) improves overall survival (OS) in glioblastoma, but previous studies suggest that patients with tumors harboring an unmethylated MGMT promoter derive minimal benefit. The aim of this open-label, phase 3 CheckMate 498 study was to evaluate the efficacy of nivolumab (NIVO)+RT compared with TMZ+RT in newly diagnosed glioblastoma with unmethylated MGMT promoter.METHODS: Patients were randomized 1:1 to standard RT (60 Gy) + NIVO (240mg every 2 weeks for 8 cycles, then 480mg every 4 weeks) or RT+TMZ (75mg/m 2 daily during RT and 150-200mg/m 2/day 5/28 days during maintenance). The primary endpoint was OS.RESULTS: A total of 560 patients were randomized, 280 to each arm. Median OS was 13.4 months (95% CI, 12.6-14.3) with NIVO+RT and 14.9 months (95% CI, 13.3-16.1) with TMZ+RT (hazard ratio [HR], 1.31; 95% CI, 1.09-1.58; P=0.0037). Median progression-free survival was 6.0 months (95% CI, 5.7-6.2) with NIVO+RT and 6.2 months (95% CI, 5.9-6.7) with TMZ+RT (HR, 1.38; 95% CI, 1.15-1.65). Response rates were 7.8% (9/116) with NIVO+RT and 7.2% (8/111) with TMZ+RT; grade 3/4 treatment-related adverse event (TRAE) rates were 21.9% and 25.1%, and any-grade serious TRAE rates were 17.3% and 7.6%, respectively.CONCLUSIONS: The study did not meet the primary endpoint of improved OS; TMZ+RT demonstrated a longer median OS than NIVO+RT. No new safety signals were detected with NIVO in this study. The difference between the study treatment arms is consistent with the use of TMZ+RT as standard of care for glioblastoma.
View details for DOI 10.1093/neuonc/noac099
View details for PubMedID 35419607