Pharmacokinetics and Drug Metabolism

National Center For Advancing Translational Sciences

Investigators

Linked publications, trials & patents

Abstract

The DMPK Lab was initially established within the Therapeutic Development Branch in the Division of Preclinical Innovation (DPI) in 2011. It became the DMPK Core in Oct 2021. The mission of the DMPK Core is to address issues related to drug absorption, biodistribution and elimination via metabolism or excretion. The DMPK Core has supported projects across NCATS intramural research labs, contributing to all stages of translational research at NCATS, from early probe development in drug discovery to Phase II clinical trials. Our major capabilities include: 1. In vitro ADME high-throughput screening (Tier I HTS assays) on kinetic aqueous solubility, membrane permeability and microsomal stability for all small molecule compounds synthesized by NCATS MedChem Scientists (3000 compounds/year). 2. Conducting customized in vitro ADME assays (Tier II assays) as required by each project’s specific needs. The common Tier II assays include metabolic stability in different species, metabolite identification (MetID), aldehyde oxidase stability in cytosol fraction, plasma stability for prodrugs and biologics, blood/plasma partition, plasma protein binding, CYP inhibition, and transporter assessments in Caco-2 and MDKC cells. 3. Performing PK studies in lab animals and bioanalytical measurements of drug concentrations in different biological fluids (e.g., blood, plasma, urine, bile) and tissue extracts. 4. Developing sensitive bioanalytical methods with UPLC-MS/MS and high-resolution accurate mass spectrometry for quantitation of small molecules (including peptides) in biologic fluids and elucidation of metabolite structures. 5. Bioanalytical method development for therapeutic macromolecules, such as recombinant human proteins, engineered proteins and gene therapies. 6. Pharmacokinetic parameter calculation, modeling and simulation. Scientific data generated from our lab in FY25 have been used for novel target validations (PMID: 40365393, and PMID: 39933019,), drug discovery and development (PMID: 38656874, PMID: 39212669, PMID: 39563805, PMID: 39625789, PMID: 39714192, PMID: 39976996, PMID: 40393055, and PMID: 40562976), in silico ADME model development (PMID: 39458588) and other research publications (PMID: 40032960). Examples of the DMPK Core contributions to recent NCATS Intramural research projects include: Development of In Silico ADME Models as A Powerful Translational Research Tool for Drug Discovery Characterization of in vitro ADME properties of a novel compound is important in drug discovery as it guides structure optimization and lead selection. We developed high-throughput assays for key ADME properties (Tier I ADME assays), such as aqueous solubility, PAMPA membrane permeability and hepatic metabolic stability in microsomes. We have collected data for 30,000 compounds synthesized or registered at NCATS from Tier I ADME assays. We also collected data on thousands of compounds from Tier II assays (e.g. human CYP450 enzymes). To ensure the quality of the datasets, we use controls in each plate and monitor the performance of these controls for all plates. We calculate Minimum Significant Ratio (MSR) for controls, a statistical parameter that characterizes the reproducibility of an assay, to evaluate assay performance. These high-quality datasets allow us to develop in silico models for these ADME properties by using Machine Learning or other AI modeling approaches. These in silico models are useful tools for medicinal chemists to design new “drug-like” molecules, which will potentially reduce the number of compounds to be synthesized during drug discovery, save valuable resources and minimize chemical wastes. Ultimately it could help to accelerate the drug discovery process. The assay protocols for ADME Tier I and Tier II assays have been published in PubChem (as of Aug 25, 2025), and the corresponding in silico models can be found at NCATS OpenData Portal. Kinetic Aqueous Solubility; PubChem AID 1645848 PAMPA Permeability (pH 7.4); AID 1508612 PAMPA Permeability (pH 5); AID 1645871 PAMPA-BBB; AID: 1845228 Rat Liver Microsome Stability; AID: 1508591 Human Liver Microsome Stability; AID01963597 Mouse Cytosol Stability; AID: 1508604 Rat Cytosol Stability Human Cytosol Stability; AID: 1508603 Human CYP3A4; AID: 1645841 Human CYP2C9; AID: 1645842 Human CYPY2D6; AID: 1645840 Human CYP3A7 Human plasma protein binding Since the launch of our website on the In Silico ADME Models in December 2021, we have ~ 8300 registered users from more than 93 countries (Figure 1). Two new models on the hepatic cytosol metabolic stability and human plasma protein binding are developed. A manuscript entitled “Developing robust human liver microsomal stability prediction models: Leveraging inter-species correlation with rat data. Pharmaceutics” was published (PMID: 39458588). 2. ADME/PK Studies for Drug Discovery and Development: In FY25, the DMPK lab has contributed significantly to several drug discovery and development projects, as illustrated in the following case studies: 1. Drug Development for PTH-IA (parathyroid hormone inverse agonist). To support the clinical trial for PTH-IA (Phase 1/2 Open-label First-in-Human Dose-Escalating Safety and Efficacy Study Evaluating Subcutaneous Administration of PTH-IA in Adults and Children with Jansen’s Metaphyseal Chondrodysplasia (JMC), we contributed to bioanalytical method development and validation for quantification of drug concentrations in human plasma and urine. In addition, the anti-drug antibody (ADA) detection method is developed and validated to assess the immunogenicity of PTH-IA in patients. These bioanalytical methods are critical for a successful clinical trial for PTH-IA. 2. Drug Development for Nomlabofusp (ClinicalTrials.gov ID NCT06681766: A Study to Assess Nomlabofusp in Adolescents and Children with Friedreich's Ataxia). Nomlabofusp is a novel recombinant fusion protein (previously referred to as CTI-1601) developed as a potential treatment for adults and children with Friedreich’s Ataxia (FRDA). It is comprised of a short, trans-activator of transcription (TAT) sequence-based cationic cell penetrant peptide fused through a diglycine linker to the amino terminus of human FXN (hFXN) containing its native MTS and mature FXN protein. Following administration, nomlabofusp (24.9 kDa) enters cells and is imported into mitochondria where it is fully processed, releasing mature FXN (14.3 kDa). Thus, nomlabofusp was designed to deliver functional FXN to mitochondria in a manner that is indistinguishable from the endogenous mature and active form of FXN. For the proof-of-concept study, we conducted preclinical PK and biodistribution studies in wide-type (WT) and Fxn-knock-out (KO) mice after IV and SC injection of nomlabofusp. Human FXN (hFXN) was quantified using a hybrid LC-MS/MS assay. Our data shown that hFXN concentrations in liver mitochodria were comparable between WT and Fxn-KO mice and had a dose dependent increase. These data suggested that nomlabofusp was able to deliver hFXN to mitochondria of tissues in KO mice. A manuscript was published recently (PMID: 40562976). 3. In Vitro Study on Brain Penetration of Natural Products Natural Products (NPs) are increasingly utilized worldwide for their potential therapeutic benefits, including central nervous system (CNS) disorders. However, a critical challenge lies in the lack of data on blood-brain barrier (BBB) penetration, which is a significant determinant for the successful development of CNS drugs. We tested our in-house NP constituent library via the Parallel Artificial Membrane Permeability Assay (PAMPA-BBB), with the aim of understanding their BBB-penetration potential. Collaborating with NCATS Tox-21 lab, we also assessed if these compounds could exhibit CNS toxicity. Our data were published in a manuscript entitled “Investigating blood-brain barrier penetration and neurotoxicity of natural products for central nervous system drug development” (PMID: 40032960). Understanding BBB permeability and assessing neurotoxicity mechanisms of NPs will significantly benefit the CNS drug discovery community. FY25 is also marked by a successful FDA approval of Sargmalin®, an inhaled formulation of GM-CSF that is approved for the treatment of autoimmune pulmonary alveolar proteinosis in adults and children, in that the NCATS DMPK lab contributed to the strategy on the bioanalytical method development for the target tissue/fluid.