Oncolytic herpes simplex virus immunovirotherapy in combination with immune checkpoint blockade to treat glioblastoma

Area of Science:

• Oncology
• Virology
• Immunotherapy

Background:

• Oncolytic viruses (oHSV) selectively kill cancer cells and stimulate anti-tumor immunity.
• Glioblastoma (GBM) is a highly immunosuppressive brain tumor resistant to current immunotherapies like checkpoint blockade.
• GBM contains cancer stem-like cells (GSCs) that contribute to tumor aggressiveness.

Purpose of the Study:

• To develop novel immunotherapeutic strategies for glioblastoma (GBM).
• To evaluate the efficacy of oncolytic herpes simplex virus (oHSV) in combination with immune checkpoint inhibitors for GBM treatment.

Main Methods:

• Utilized a syngeneic GSC-derived orthotopic GBM model (005).
• Administered oHSV engineered to express IL-12 in combination with anti-PD-1 and anti-CTLA-4 checkpoint inhibitors.

Main Results:

• Curative therapy for GBM required a combination of oHSV expressing IL-12, anti-PD-1, and anti-CTLA-4.
• The anti-tumor response was dependent on the intricate interplay of CD4+, CD8+ T cells, and macrophages.

Conclusions:

• Combination immunotherapy involving oHSV, IL-12, and dual checkpoint blockade can overcome GBM's immunosuppressive microenvironment.
• This strategy holds potential for treating aggressive brain tumors like glioblastoma.