BIOS-05. PEPTIDE-BASED VACCINES VERSUS DENDRITIC CELL-BASED VACCINE THERAPIES FOR PATIENTS WITH GLIOBLASTOMA: A NETWORK META-ANALYSIS OF CONTROLLED CLINICAL TRIALS

Abstract BACKGROUND Glioblastoma (GBM) is the most prevalent primary CNS malignancy in adults, often with a bleak prognosis. Reports suggest the efficacy of dendritic cell vaccines (DCV) and peptide vaccines in extending overall survival (OS). We aimed to compare their efficacy using network meta-analysis (NMA). METHODS We systematically searched PubMed, Cochrane database, SCOPUS, and Clinicaltrials.gov up to February 2024 for controlled trials on DCV or peptide vaccines for GBM. NMA was conducted using the frequentist approach to obtain direct and indirect comparisons of each vaccine. Pairwise analyses were performed using the inverse variance method, comparing each vaccine’s efficacy. PEPvIII-KLH and Rindopepimut were merged into “Peptide-based vaccines” [PEP], and standard of care (SOC) and (Placebo + SOC) were merged. Primary outcome: hazard ratio (HR) of overall survival with 95% confidence intervals. RESULTS Analysis included 5 studies with 451 patients (vaccine arm) and 445 controls, with SOC/[Placebo + SOC] as reference. Common effects model showed DCV + SOC significantly reduced the HR to 0.3385 [0.1753; 0.6539], while the peptide-based vaccine + SOC reduced the HR to 0.8276 [0.6960; 0.9840]. In the random effects model, DCV + SOC had an HR of 0.3132 [0.0839; 1.1688], and the peptide-based vaccine + SOC had an HR of 0.3888 [0.1383; 1.0928]. Heterogeneity: tau^2 = 0.6473, tau = 0.8045, I^2 = 77.7% [39.5%; 91.8%]. In a pairwise meta-analysis comparing the DCV+SOC and SOC/[Placebo + SOC] consisting of 2 trials, the common and random effects models both estimated an HR of 0.3385 [0.1753; 0.6539, I^2 = 0.0%]. Comparing the PEP+SOC and SOC/[Placebo + SOC] based on 3 trials, the common effect model estimated an HR of 0.8276 [0.6960; 0.9840], while the random effects model estimated an HR of 0.3874 [0.1360; 1.1039, I^2 = 84.4%]. CONCLUSION Based on current evidence, DCV vaccines perform better than peptide-based vaccines in reducing mortality in GBM patients. Further trials are required to validate their efficacies.