Efficacy and Safety of Immunotherapy and Standard of Care in High-Grade Gliomas: A Systematic Review and Meta-analysis

Abstract BACKGROUND: Immunotherapy combined with standard of care (SOC) is often used for high-grade glioma (HGG). There are few comparisons of immunotherapy with SOC treatment or without SOC treatment (IMT) versus SOC. It is important to understand what interventions exist and their relative effectivenesses. METHODS: The Cochrane Library, Embase, Medline, and the Web of Science Core Collection were systematically searched by two librarians. Retrieved hits were screened for inclusion. Subgroup analysis was used to examine the main factors associated with overall survival (OS) and progression-free survival (PFS), which were used as primary endpoints to assess the efficacy and safety of IMT. This study was registered with PROSPERO, number CRD42019112356. RESULTS: The search yielded 2,315 results, of which 11 met the eligibility criteria. We identified 6 publications through exploration. Compared to SOC alone, IMT including viral therapy (VT) and dendritic cell vaccination improved the OS (HR = 0.55, 95% CI 0.42-0.72; p < 0.0001) and PFS (HR = 0.67, 95% CI 0.53-0.84; p = 0.0005). CONCLUSIONS: We found that IMT in the era of TMZ has an improved effectiveness over SOC. Our findings support the use of immunotherapy for brain tumors to improve HGG outcomes.