ALVIS UPITIS/GETTY IMAGES Biopharmaceutical drug development and therapeutic use are two components of integrated pharmaceutical medicine; drugs are developed to provide safe, therapeutic benefit to patients.1 Patient safety is of considerable current interest among multiple stakeholders in many countries, including the United States. The Food and Drug Administration (FDA), patients, and their prescribing physicians all have a vested interest in drug safety. The topic has attracted attention from Congress, the Supreme Court, the Institute of Medicine (IOM), pharmaceutical companies, patient advocacy groups, and the media. Given that patient safety is of overriding importance, safety considerations are addressed throughout lifecycle drug development.2 Extensive safety evaluations occur throughout the range and diversity of preapproval clinical trials, postmarketing trials, and postmarketing surveillance. Similarly motivated investigations occur beforehand in two other phases of lifecycle development: drug discovery/drug design and nonclinical development programs. While attention in this article focuses on safety assessments in preapproval clinical development and therapeutic use, references are provided for readers who wish to learn more about nonclinical safety evaluations.3