The Impact of FDA’s Guidance on Clinical Trials for Radiopharmaceuticals

On Aug. 18, 2025, FDA published a draft guidance, titled Oncology Therapeutic Radiopharmaceuticals: Dosage Optimization During Clinical Development, that was created to assist drug sponsors with identifying an optimized dosage for radiopharmaceutical therapies for cancer indications during clinical development (1). The guidance addresses clinical development before submitting a marketing application for a new indication and usage.

Pharmaceutical Technology® spoke with Michael Ritchie, chief commercial officer of Champions Oncology, to find out how the new guidance might impact the development and approval of radiopharmaceuticals and what some of the challenges are for conducting clinical trials for these treatments.

“Radio pharmaceuticals have been around for about 100 years, and classical radiopharma relied on something called EBRT, or external beam radiotherapy, and that is essentially delivering a radio beam to the patient from an external source,” Ritchie says. “But we're now looking at a new wave of therapies which are injected systemically, and quite frankly, we just don't know enough about them. FDA has released new guidance that has said, hey, we want you to come to the table with a better understanding of pharmacodynamics potential liabilities from a toxicity perspective, therapeutic window. But we also want you to design your clinical trials in such a way that we can get an idea on dosimetry.”

Click the video above to watch the full interview.

Reference

1. FDA. Oncology Therapeutic Radiopharmaceuticals: Dosage Optimization During Clinical Development. Draft Guidance for Industry (OCE, CDER, August 2025). https://www.fda.gov/regulatory-information/search-fda-guidance-documents/oncology-therapeutic-radiopharmaceuticals-dosage-optimization-during-clinical-development