The Emerging Role of Oncolytic Virotherapy in Glioblastoma Management

Glioblastoma (GBM) is an aggressive and common form of central nervous system primary malignant tumor in adults. GBM accounts for about half of all gliomas. Despite maximal resection, radiotherapy, and temozolomide, median survival is still 12-15 months because of tumor heterogeneity, diffuse infiltration, and therapeutic resistance. Recurrence is nearly universal, underscoring the need for novel therapies. Oncolytic virotherapy demonstrates a promising strategy that combines direct tumor cell lysis with immune activation. Tumor-selective viruses replicate within malignant cells, induce cell death, and release tumor antigens, thereby reshaping the immunosuppressive microenvironment. Several viral backbones have advanced to clinical testing, including adenovirus (DNX-2401), herpes simplex virus (G47Δ, G207), poliovirus (PVS-RIPO), measles virus (MV-CEA), reovirus (pelareorep), vaccinia virus (Pexa-Vec), and vesicular stomatitis virus (VSV-GP). The approval of G47Δ in Japan for malignant glioma marks a milestone, with early trials demonstrating safety and signals of durable benefit, particularly in combination regimens. Current research emphasizes engineering viral genomes to enhance selectivity, immune stimulation, and resistance to clearance, while exploring synergistic combinations with radiotherapy, chemotherapy, immune checkpoint inhibitors, and tumor-treating fields. Advances in delivery, such as convection-enhanced infusion and blood-brain barrier modulation, are also under investigation. Despite obstacles, oncolytic virotherapy holds significant potential within multimodal GBM strategies.