More than 138,000 people in the United States and 1.4 million people worldwide are struggling with malignant brain tumors. The average five-year survival rate of people with the most common malignant brain tumor—glioblastoma multiforme—is less than 5 percent and there have been no notable improvements in the last three decades. The Ivy Brain Tumor Center is using phase 0 clinical trials to provide individualized treatment to patients with brain tumors. The U.S. Food and Drug Administration introduced phase 0 trials in 2004 to address concerns about the slow pace and high cost of drug development. The phase 0 trial is used to quickly identify how a drug works in a patient and whether it should be fast-tracked for further development. We spoke to Nader Sanai, director of the Ivy Brain Tumor Center and chief of neurosurgical oncology at the Barrow Neurological Institute, about phase 0 clinical trials, how they work, and how they are allowing the center to take a precision medicine approach to treating patients with brain tumors.