Oncology Drug Approvals: Evaluating Endpoints and Evidence in an Era of Breakthrough Therapies.

With the Breakthrough Therapy Designation program adding to the tools that the U.S. Food and Drug Administration (FDA) has for expediting drug development, the FDA reassessed the endpoints needed for approval of transformative therapies. Although the demonstration of an improvement in overall survival remains the gold standard for drug approval, innovation in cancer research has led to use of other endpoints in regulatory decision‐making. These endpoints include substantially delaying tumor progression or extending progression‐free survival, substantially reducing tumor size for a prolonged time, improving objective response rate and duration of response, or improving cancer‐related symptoms and patient function.