Toxicokinetics, Pharmacokinetics, And Pharmacodynamics

Understanding a new drug’s absorption, distribution, metabolism, and excretion (ADME) is essential to ensure its safety and efficacy for human use. This understanding is built through the collection and analysis of pharmacokinetic (PK) and pharmacodynamic (PD) data, which together constitute approximately 25% of a drug’s package insert or label content.

The characterization of PK/PD effects begins with nonclinical toxicokinetic (TK) studies in animal models. These studies are designed to define the drug’s chemical properties, including its pharmacology and toxicology, while informing the development of downstream clinical protocols. Conducted prior to the submission of Investigational New Drug (IND) applications to the FDA or other global regulatory agencies, these nonclinical studies generate critical data that establish parameters for subsequent clinical trials.

In this issue, we explore how the understanding of a novel drug’s PK and PD properties is rooted in nonclinical studies and evolves through early-phase clinical trials, laying the groundwork for regulatory approval and therapeutic success.