A door has been opened for clinical trial participation by patients whose disease has spread to the brain. Selection processes often exclude these patients or require that they first receive radiation therapy due primarily to uncertainty about whether the drugs could reach tumors in the brain and be effective. The challenge has been getting the drugs past a vascular seal called the blood-brain barrier that protects the brain from toxins carried by the blood. Now researchers at The University of Texas MD Anderson Cancer Center have opened access to new, promising drugs for these patients by testing two types of therapies and demonstrating their significant success at shrinking metastatic brain tumors in at least 50 percent of patients in multi-center clinical trials. It is thought that the treatment worked in this case because immune checkpoint drugs treat T cells, which can get through the barrier, rather than the hit tumor directly. The study results demonstrate that brain tumor patients can show signficant improvement without first having undergone radiation therapy and should have access to clinical trials.