Advances and challenges in glioblastoma immunotherapy: a meta-analysis of immune checkpoint inhibitors

Abstract Introduction Glioblastoma (GBM) remains the most aggressive primary brain tumor, with poor prognosis and limited therapeutic options. Immune checkpoint inhibitors have shown promising results in solid tumors, but their role in GBM remains uncertain. Methods A PRISMA-based systematic review and meta-analysis including studies evaluating checkpoint inhibitors in newly diagnosed and recurrent GBM. Random-effects models calculated pooled hazard ratios for OS and PFS. Results Eleven studies were included, six ( n = 2,019) incorporated into pooled survival analyses. No significant OS benefit was observed (HR = 1.12; 95% CI: 0.97–1.29; I 2 = 0%; p = 0.138). PFS showed significant differences (HR = 1.34; 95% CI: 1.06–1.68; I 2 = 74.3%; p = 0.013). Grade ≥ 3 toxicity occurred in 32.1% of patients. Conclusion Checkpoint inhibitors did not significantly improve OS or PFS in GBM patients and were associated with substantial toxicity and inter-study heterogeneity.