The CheckMate 143 Phase 3 randomized clinical trial evaluated the efficacy and safety of nivolumab compared with bevacizumab in patients with recurrent glioblastoma. The study included 369 patients who were randomized 1:1 to receive either nivolumab (3 mg/kg) or bevacizumab (10 mg/kg) every 2 weeks until disease progression, unacceptable toxic effects, or death. The primary endpoint was overall survival (OS), and secondary endpoints included progression-free survival (PFS) and objective response rate (ORR). At a median follow-up of 9.5 months, the median OS was comparable between the nivolumab (9.8 months) and bevacizumab (10.0 months) groups (hazard ratio [HR] 1.04, 95% CI 0.83-1.30, P = .76). The 12-month OS rate was 42% in both groups. The ORR was higher with bevacizumab (23.1%) compared with nivolumab (7.8%). Grade 3/4 treatment-related adverse events (TRAEs) were similar between the groups, with no unexpected neurological TRAEs or deaths due to TRAEs. Subgroup analyses suggested that patients with methylated *MGMT* promoter status and no baseline corticosteroid use may benefit more from nivolumab. The study concluded that nivolumab did not improve OS compared with bevacizumab in patients with recurrent glioblastoma, but the safety profile was consistent with other tumor types.The CheckMate 143 Phase 3 randomized clinical trial evaluated the efficacy and safety of nivolumab compared with bevacizumab in patients with recurrent glioblastoma. The study included 369 patients who were randomized 1:1 to receive either nivolumab (3 mg/kg) or bevacizumab (10 mg/kg) every 2 weeks until disease progression, unacceptable toxic effects, or death. The primary endpoint was overall survival (OS), and secondary endpoints included progression-free survival (PFS) and objective response rate (ORR). At a median follow-up of 9.5 months, the median OS was comparable between the nivolumab (9.8 months) and bevacizumab (10.0 months) groups (hazard ratio [HR] 1.04, 95% CI 0.83-1.30, P = .76). The 12-month OS rate was 42% in both groups. The ORR was higher with bevacizumab (23.1%) compared with nivolumab (7.8%). Grade 3/4 treatment-related adverse events (TRAEs) were similar between the groups, with no unexpected neurological TRAEs or deaths due to TRAEs. Subgroup analyses suggested that patients with methylated *MGMT* promoter status and no baseline corticosteroid use may benefit more from nivolumab. The study concluded that nivolumab did not improve OS compared with bevacizumab in patients with recurrent glioblastoma, but the safety profile was consistent with other tumor types.