DAY 1: Sunday, September 21, 2025

Human radiolabeled mass balance studies are an important component of the clinical pharmacology programs supporting the development of new investigational drugs. These studies allow for understanding of the absorption, distribution, metabolism, and excretion (ADME) of the parent drug and metabolite(s) in the human body. Understanding the drug's disposition as well as metabolite profiling and abundance via mass balance studies can help inform the overall drug development program. Recently, U.S. FDA published the final guidance on “Clinical Pharmacology Considerations for Human Radiolabeled Mass Balance Studies” (https://www.fda.gov/media/158178/download). This short-course will discuss the purpose and design of human mass balance study, metabolite profiling, data analysis and interpretation. When to conduct mass balance study in drug development and how the data may be used to support various decision making related to drug-drug interactions and supporting PBPK modeling will be discussed. New development and regulatory expectation and perspectives will also be provided.

This short course will focus on the role of clinical probes and biomarkers in evaluating transporter-mediated drug-drug interactions (DDIs). Attendees will gain insights into the emerging importance of transporter biomarkers in drug development, with emphasis on how they inform and confirm DDI risk of an investigational drug. The short-course will also include the selection and application of clinical drug probes to assess transporter function, study design considerations, and the interpretation of resulting data. Regulatory perspectives of biomarkers as well as exogenous probes will be discussed to highlight best practices and emerging guidelines for incorporating transporter biomarkers and drug probes into DDI risk assessments during drug development.