Food and Drug Administration requirements for testing and approval of new radiopharmaceuticals.

In March 2004, the Food and Drug Administration (FDA) published a report entitled Challenge and Opportunity on the Critical Path to New Medical Products in which it explained the critical path to medical product development and called for a nationwide effort to modernize the critical-path sciences with the aim of moving medical product development and patient care into the 21st century. The report identified medical imaging and imaging biomarkers as potential clinical development tools to facilitate medical product development and to help minimize drug attritions and development timelines. Also, in recent years, basic research on receptor-based imaging has led to an increase in the new investigational radiopharmaceuticals, many of which are in basic research stages in academic institutions. It is therefore an opportune time to review the FDA requirements for testing and approval of new radiopharmaceuticals to further the cause of development and approval of newer medical imaging and therapeutic agents. Although the radiopharmaceutical-development process aligns well with the drug-development process for conventional pharmaceuticals, it has its own challenges and unique considerations. For example, unique issues surrounding short-lived positron emission tomography drugs have necessitated revisions and refinements to the existing regulations. The FDA Modernization Act mandate has finally resulted in the publication of new cGMPs (current good manufacturing practice) for positron emission tomography drugs. Often, the radiopharmaceutical community is not well-informed about the regulatory pathways and scientific basis for the regulations they are subjected to. Questions, such as (1) "Do I need an investigational new drug (IND) or can I do my investigation under an RDRC (radioactive drugs research committee) oversight?" (2) "What type of information on radiopharmaceutical product quality is needed for an IND?" (3) "What level of cGMPs I am expected to operate under?" (4) "Do I need a traditional IND or can I perform studies under an exploratory IND?" (5) "What are the IND-enabling pharmacology and toxicology studies?" (6) "Is my practice consistent with pharmacy compounding or do I need to file an application with the FDA?", for example, are a source of confusion to the radiopharmaceutical community. This review provides an overview of FDA's drug development and approval process with special emphasis on radiopharmaceuticals and attempts to clarify many regulatory issues and questions by providing appropriate discussion and FDA references.