Advancing Glioblastoma Treatment: Challenges and Opportunities of Immune Checkpoint Inhibition

Glioblastoma is the most aggressive and common malignant brain tumor in adults, with poor prognosis despite improvements in standard treatments such as surgery, radiation, and chemotherapy with temozolomide. Immune checkpoint inhibitors have emerged as a promising approach to strengthen the immune system’s ability to fight GBM by targeting the mechanisms that allow the tumor to evade immune detection. However, GBM presents significant challenges to the effectiveness of ICIs. These include its highly immunosuppressive environment, the protective barrier of the blood-brain barrier, and a low rate of genetic mutations, which makes it harder for the immune system to recognize the tumor as a threat. This review discusses the current knowledge on ICIs in treating GBM, focusing on both the successes and limitations seen in clinical trials. While ICIs as standalone treatments have shown limited success, combining them with other therapies like radiation, vaccines, or gene therapy has shown promise in enhancing the immune response and improving patient outcomes. The development of reliable biomarkers and innovative combination therapies is crucial to overcoming GBM’s resistance to immunotherapy. The review emphasizes the urgent need for personalized treatment strategies and further research to fully realize the potential of ICIs in managing this challenging disease.