Dr. Susan Ellenberg is Professor of Biostatistics, Center for Clinical Epidemiology and Biostatistics, and Associate Dean for Clinical Research, University of Pennsylvania School of Medicine.Dr. Ellenberg's research has focused on practical problems and ethical issues in designing, conducting and analyzing data from clinical trials, including surrogate endpoints, data monitoring committees, clinical trial designs, adverse event monitoring, vaccine safety and special issues in cancer and AIDS trials. At Penn, in addition to her teaching and administrative duties she serves as senior statistician for two multicenter clinical trials and directs the Biostatistics Core of the Penn Center for AIDS Research.Prior to her appointment at Penn, Dr. Ellenberg held positions of increasing responsibility in the federal government. From 1993 to 2004 she served as Director, Office of Biostatistics and Epidemiology in the Center for Biologics Evaluation and Research (CBER) at the U.S. Food and Drug Administration; prior to that she served as the first Chief of the Biostatistics Research Branch in the Division of AIDS, National Institute of Allergy and Infectious Diseases (1988-1993), and served in the Biometric Research Branch in the Cancer Therapy Evaluation Program, National Cancer Institute (1982-1988). During Dr. Ellenberg's tenure at FDA she played a leading role in the development of international standards for design and analysis of clinical trials performed by the pharmaceutical industry, developed productive programs for postmarketing safety surveillance of biological products, and coordinated the development of policy for the establishment and operation of clinical trial data monitoring committees.Dr. Ellenberg is a Fellow of the American Statistical Association, the Society for Clinical Trials and the American Association for the Advancement of Science, and is an elected member of the International Statistical Institute. Her book, Data Monitoring Committees in Clinical Trials: A Practical Perspective, co-authored with Drs. Thomas Fleming and David DeMets, was named WileyEurope Statistics Book of the Year for 2002.