Nonclinical Recommendations for Radiopharmaceuticals: FDA Drafts Guidance

The US Food and Drug Administration (FDA) on Tuesday released draft guidance on nonclinical study recommendations for microdose radiopharmaceutical diagnostic drugs.

The 7-page draft seeks to help developers of these microdose radiopharmaceutical diagnostic drugs on the nonclinical studies recommended to support human clinical trials and marketing authorization.

The draft specifically discusses how to refine nonclinical study recommendations for this class of drugs and is intended to reduce the use of animals, time and resources expended in microdose radiopharmaceutical diagnostic drug development without compromising patient safety.

Background

"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 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, so FDA recommends that sponsors "tailor the amount and type of nonclinical supporting data to account for the low potential for adverse events."

Nonclinical Studies

The draft recommends eight different study times, including pharmacology, extended single-dose toxicity in one species (usually a rodent), genotoxicity, safety pharmacology, repeat dose toxicity, pharmacokinetic, developmental and reproductive toxicity and special toxicity studies.

"The Agency strongly recommends that the sponsor schedule a pre-IND meeting for evaluating the drug development recommendations for a specific drug," the draft says.

Microdose Radiopharmaceutical Diagnostic Drugs: Nonclinical Study Recommendations