Human Radiolabeled Mass Balance Studies Supporting New Drugs Approved by FDA Between 2019 and 2023

Human radiolabeled mass balance studies are essential for understanding the absorption, distribution, metabolism, and excretion (ADME) of investigational drugs.The Food and Drug Administration (FDA) guidance recommends conducting these studies for new molecular entities (NMEs) to inform drug development programs.Herein, we analyzed new drug applications (NDAs) approved between 2019-2023, and results showed continued alignment with previous 2014-2018 findings and with recommendations in the FDA guidance.These studies remain foundational to drug development but are evolving to incorporate scientific innovations. | Importance and Prior Experience with Human Radiolabeled Mass Balance StudiesHuman radiolabeled mass balance studies, which characterize the ADME of investigational drugs, are critical components of clinical pharmacology programs [1][2][3][4].These studies provide essential information for understanding drug disposition, informing metabolite safety assessments, and guiding drug-drug interaction evaluations during drug development.