Glioblastoma (or glioblastoma multiforme, GBM) is the most common and aggressive type of primary brain cancer. Globally, the incidence of glioblastoma is approximately 1 to 2 in 100,000 people annually. Glioblastoma is considered one of the most hypoxic (oxygen deprived) of all solid tumors.
Glioma tumors arise from the glial cells which form the tissue that surrounds and protects other nerve cells within the brain and spinal cord. The standard of care for glioblastoma is surgical intervention to remove the tumor followed by radiation therapy and chemotherapy using temozolomide. These treatments may be used alone, but are usually used in combination. Often, only a portion of the tumor can be safely removed because malignant cells have infiltrated brain tissue in functionally crucial areas, allowing the potential for rapid recurrence of the tumor. Thus, a combination of radiation therapy and chemotherapy are often used following surgery as part of standard-of-care treatment.
Previous clinical trials have demonstrated median overall survival for patients receiving combination treatment is 14.6 months, an improvement of 3 months over radiotherapy alone. Treatment with the combination also resulted in an increase in 2 year survival from 10.4% to 26.5%. This improvement in survival demonstrates that it is possible to achieve improved results by combining other treatment modalities with radiation therapy. However, it also demonstrates the substantial remaining unmet medical need, with almost 3 out of 4 patients dead within 2 years of diagnosis.