Microdose Radiopharmaceutical Diagnostic Drugs: FDA Finalizes Guidance
The US Food and Drug Administration (FDA) on Monday finalized guidance to help sponsors of microdose radiopharmaceutical diagnostic drugs on the nonclinical studies recommended to support human clinical trials and marketing applications.In terms of changes between the draft from last September and the final guidance, FDA said it now incorporates comments received, includes a few editorial changes and a new sentence clarifying the definition of the term diagnostic radiopharmaceutical.
The seven-page guidance defines diagnostic radiopharmaceutical as “(1) a drug that is intended for use in the diagnosis or monitoring of a disease or a manifestation of a disease in humans and that exhibits spontaneous disintegration of unstable nuclei with the emission of nuclear particles or photons or (2) any nonradioactive kit or nuclide generator that is intended to be used in the preparation of such a drug.”
FDA notes that these are drugs that are used in nuclear medicine procedures, including “planar imaging, single photon emission computed tomography, positron emission tomography, and in combination with other radiation detection probes.”
The guidance also explains microdosing.
“For radiopharmaceutical diagnostic drugs, the microdose evaluated during early clinical trials does not differ significantly from the microdose intended for marketing approval and is less than or equal to 100 micrograms (µg),” FDA says. “Because these diagnostic drugs are administered using a dose at the low end of the dose-response curve, dose-related adverse events are unlikely to occur. The Agency recommends that sponsors tailor the amount and type of nonclinical supporting data to account for the low potential for adverse events.”
The recommendations in this guidance are intended to reduce the time and resources expended in microdose radiopharmaceutical diagnostic drug development, FDA notes, without compromising patient safety.
FDA also recently published draft guidance on oncology therapeutic radiopharmaceuticals’ nonclinical studies and labeling.
Microdose Radiopharmaceutical Diagnostic Drugs: Nonclinical Study Recommendations Guidance for Industry