Clinical outcome assessments in neuro-oncology: a regulatory perspective.

Overall survival, progression-free survival, and to a lesser extent objective response rate, have long been the most widely accepted endpoints used to evaluate clinical benefit in oncology trials. More recently, clinical outcome assessments (COAs) that measure the impact of disease and treatment on patients' symptoms and function have been recognized as having potential to be an integral component of the risk/benefit analysis of new therapies. Although COAs have been used to evaluate cognitive and physical functioning in neurological diseases, assessing patient-centered outcomes in individuals with malignant brain tumors presents unique challenges. The approach to developing appropriate instruments to measure COAs in neuro-oncology should include identifying areas requiring new tools, reviewing existing tools that may be suitable or adapted for use in clinical trials, and engaging early with regulatory agencies to standardize a set of well-defined and reliable instruments to quantify important patient-centered outcomes.