Regulatory concerns in human gene therapy.

Gene therapy in humans is now being undertaken in an investigational setting. Such therapy involves the administration of biological products to human patients. A document entitled, "Points to Consider in Human Somatic Cell Therapy and Gene Therapy" has been prepared by the Center for Biologics Evaluation and Research (CBER) of the Food and Drug Administration (FDA) and is published elsewhere in this issue. This paper provides explanatory material about the CBER regulatory process and the scientific and regulatory basis for the requests for data in that document.