Can immunotherapy treat glioblastoma? Understanding the latest study

A new study has revived hope for the role of immunotherapy in treating glioblastoma, the most aggressive and deadly form of brain cancer in adults. The study used a type of immunotherapy known as checkpoint inhibitors, which train the immune system’s T cells to fight cancer. Although checkpoint inhibitors have greatly increased overall survival for some types of cancer, such as melanoma, early clinical trials failed – until now – to show any benefit for glioblastoma.   We sat down with John de Groot, M.D., professor and interim chair of Neuro-Oncology, who led the MD Anderson portion of the study, to learn more about the latest progress in immunotherapy for glioblastoma. How did this clinical trial work? The Phase II randomized clinical trial was led by researchers from UCLA and conducted at six other institutions, including here at MD Anderson. We enrolled recurrent glioblastoma patients – people whose tumors had returned after their initial treatment. Nearly all glioblastomas recur, and when this happens, median survival drops to less than a year. The study had two different arms. In one arm, patients received pembrolizumab, an immune checkpoint inhibitor, both before and after surgery. In the other arm, patients only received the drug after surgery. How was this study different from previous clinical trials studying immunotherapy in glioblastoma patients? Most glioblastoma clinical trials only give the new drug at the time of recurrence, usually without surgery. Previous studies of pembrolizumab in glioblastoma that were designed this way haven’t shown a survival benefit. One of the goals of this study was to look at the drug’s effect on tumor biology. In order...