Progression-free survival (PFS) from histologic diagnosis for all patients for whom methylguanine methyltransferase (MGMT) methylation status could be assessed is shown (n = 13). The blue line shows patients with unmethylated MGMT (n = 7) who had a median PFS of 22.0 months (95% CI, 14.9 to ∞ months), and the gold line shows patients with methylated MGMT (n = 6) who had a median survival of 10.9 months (95% CI, 6.5 to 15.4 months). When adjusted for age and Karnofsky performance status, patients who had been vaccinated with unmethylated MGMT had an unexpectedly significantly longer PFS (hazard ratio, 0.17; 95% CI, 0.032 to 0.90; P = .037).