Jacqueline B. Tiley, PhD, is an Assistant Professor in the Division of Pharmacotherapy and Experimental Therapeutics at the UNC Eshelman School of Pharmacy. She obtained her MSc in Pharmacy and PhD from the University of Basel in Switzerland. Dr. Tiley completed her postdoctoral training at the University of North Carolina at Chapel Hill. Her research program focuses on disease- and drug-mediated alterations in hepatic and placental transport proteins and its impact on drug disposition and toxicity.

Dr. Joanne Wang is a Professor of Pharmaceutics at the University of Washington School of Pharmacy in Seattle. She earned her PhD in Pharmaceutical Chemistry and completed postdoctoral training at the University of California, San Francisco. Her research focuses on membrane transporters and their roles in xenobiotic and nutrient disposition, pharmacokinetics, and drug-induced toxicity. Her current work examines placental transporters in fetal nutrient uptake and drug exposure and applies systems pharmacology and PBPK modeling to predict transporter-mediated drug exposure during pregnancy and lactation.

Dr. Samuel Arnold joined the Department of Pharmaceutics at the University of Washington as an Assistant Professor in 2023, and his research predominantly focuses on characterizing exposure-response relationships for therapeutic treatment of infectious diarrhea. This work includes the development of novel in vitro and in vivo models for enteric pathogens such as Shigella and clinical pharmacology support for clinical trials investigating novel treatments for enteric infections. In addition to his work on enteric infections, Dr. Arnold is the director of the Bioanalysis and Pharmacokinetics Lab at the University of Washington. This lab supports a variety of internal and external projects using mass spectrometry to quantify small molecules and proteins in complex tissue samples.

Donglu earned his Ph.D. in Organic Chemistry under Professor C. Dale Poulter at the University of Utah in 1990, studying the biosynthesis of archaebacterial membrane lipids. He continued his postdoctoral work at Utah, refining his skills in cloning and purification techniques, and then joined the FDA, where he first explored drug metabolism in microbial systems. Throughout his career, Donglu has combined scientific rigor with creativity, co-inventing mass defect filtering, a tool that revolutionized metabolite identification and has been widely adopted across mass spectrometry platforms.

Donglu’s achievements span decades and have had global impact. He was a key scientific lead in the development of Eliquis (apixaban), one of the top-selling drugs in the U.S., and contributed to the development of Polivy, an antibody-drug conjugate. His work on gemfibrozil glucuronide and atazanavir led the FDA to adopt these compounds as standard probes in clinical drug-drug interaction studies, directly shaping regulatory guidance. He has published more than 136 papers, authored numerous book chapters, and holds patents that have advanced the science of drug metabolism.

At both Bristol-Myers Squibb and Genentech, Donglu has been recognized for his ability to bridge discovery and development. He is known internationally for his expertise, invited as a keynote speaker at the Gordon Research Conference on Drug Metabolism, and has inspired countless colleagues with his commitment to “Science without Borders.”

Chen Chen is a postdoctoral fellow in the Department of Drug Metabolism and Pharmacokinetics at Genentech, Inc. He earned his Ph.D. from the Tri-Institutional Chemical Biology program, a joint offering from Weill Cornell Medicine, Memorial Sloan Kettering Cancer Center, and The Rockefeller University. His research focuses on the mechanistic understanding of drug clearance pathways, as well as nanoparticle drug assembly and tumor-targeted delivery.

Murali Subramanian is a director of research in DMPK at Gilead Sciences where he is a project leader and DMPK representative for multiple programs in discovery and development across several therapeutic areas. Prior to this, he worked in Janssen Pharmaceutica and Biocon Bristol Myers Squibb Research Center. He obtained his PhD in Chemical and Biological Engineering from Iowa State University and was a postdoctoral and research fellow under Professor Timothy S Tracy and Professor Rory Remmel at the University of Minnesota. His interests lie in the mechanistic understanding and translation of DMPK and ADME principles.

Xinning Yang is a Policy Lead in Guidance & Policy team (GPT) under the Office of Clinical Pharmacology (OCP), CDER of FDA. He received his Ph.D. in Pharmaceutical Science from University at Buffalo, mentored by Dr. Marilyn Morris. In the past, as a clinical pharmacology reviewer, he reviewed a number of IND/NDA submissions contributing to the benefit/risk assessment of neurology drug products. His current primary focus is guidance and policy development and implementation in various areas, focusing on drug metabolism, pharmacokinetics, and drug-drug interactions related Clinical Pharmacology issues. He is active in research and led or co-led multiple research projects funded internally. He served as the Chair of Transporter Scientific Interest Group of OCP from 2014 to 2015. He has received a number of individual and team awards from CDER which recognized his contribution to regulatory science and research. He is the Co-Chair of Transporter Focus Group of ISSX and a member of International Transporter Consortium (ITC) committee. He is participating in the International Council Harmonization (ICH) M12 DDI guidance working group. He has been an invited speaker for multiple conferences and workshops and organized symposia at several meetings.

Dr. Obach’s distinguished career at Pfizer Global Research and Development exemplifies the award’s spirit. Rising from Research Scientist to Vice President of Scientific Research, he has advanced global understanding of drug metabolism, enzyme kinetics, bioactivation, and drug-drug interactions. His work has profoundly influenced drug discovery and development, improving the prediction of human pharmacokinetics across therapeutic areas.

A prolific scientist, Dr. Obach has authored more than 240 publications, achieved an H-Index of 76, and garnered over 12,000 citations. His groundbreaking research and mentorship have earned him a global reputation as the “godfather of applied ADME sciences.

Dr. Obach’s contributions extend beyond research. A committed leader within ISSX, he has served as President (2022–2023), President-Elect (2020–2021), and Chairman of the Scientific Advisory Board (2016–2020), as well as a journal editor for Drug Metabolism and Disposition and Xenobiotica.

This year’s award marks a historic milestone, as Dr. Obach becomes the first industry scientist to receive the R.T. Williams Distinguished Scientific Achievement Award. His career stands as a testament to the excellence, innovation, and dedication that define the ISSX community.

Upendra Dahal is currently a Scientific Director in Pharmacokinetic and Drug Metabolism (PKDM) Department at Amgen. He represents PKDM in multi-disciplinary teams from discovery to development, oversees small molecule projects and outsourcing of ADME studies, and supervises scientists and PTRs. Proficient in designing in vitro and in vivo studies to characterize/understand PKDM properties of the drug candidates, provides recommendations to the teams to design better compounds with minimal metabolic and DDI liabilities. Leading the biotransformation group for small molecule drugs, Upendra reviews data, monitors studies, and addresses PKDM challenges to mitigate risks. His role involves preparing as well as reviewing regulatory documents for IND and NDA submissions. Previously worked at Celgene and Pfizer, Upendra boasts diverse research interests, evidenced by a strong track record of peer-reviewed publications across various domains. Upendra received his PhD focusing on enzyme kinetics and drug metabolism from Washington State University under supervision of Prof. Jeff Jones.

Xin Chen, Ph.D., is a Postdoctoral Research Fellow at the Center for Translational Medicine, School of Pharmacy, University of Maryland, Baltimore (UMB). He earned his Bachelor’s degree in Basic Pharmacy from China Pharmaceutical University (CPU) in 2019 and his Ph.D. in Pharmaceutics from the University of Washington (UW) in 2025. Dr. Chen’s research focuses on pregnancy pharmacology, drug transporters, cannabinoids, and quantitative modeling and simulation. He has authored nine peer-reviewed publications, including five as first author, and has received several fellowships and awards during his graduate training.

Aditya (Adi) R. Kumar, Ph.D., is a Principal Scientist at Genentech. He earned his B.S. in Molecular, Cellular, and Developmental Biology from the University of Washington in 2017 and his Ph.D. in Pharmaceutics from the University of Washington in 2023, under the mentorship of Dr. Jashvant Unadkat. His research expertise lies in DMPK, specifically in leading IND-enabling strategies and translational modeling to inform drug discovery and development. His work focuses on uncovering mechanistic drivers of pharmacokinetic processes, including the use of PBPK modeling to predict human efficacious doses and assess clinical liabilities. He has also conducted extensive research into pregnancy pharmacokinetics, cannabinoid disposition, and tumor microenvironment modeling. He has authored nine publications in journals such as Nature Communications and Clinical Pharmacology & Therapeutics.

Jashvant (Jash) Unadkat, Ph.D. is a Professor in the Dept. of Pharmaceutics at the School of Pharmacy, University of Washington, Seattle.   He received his Bachelor’s degree in Pharmacy (B.Pharm.) from the University of London (1977), his Ph.D. from the University of Manchester and his postdoctoral training at the University of California at San Francisco.  He held the Milo Gibaldi Endowed Professorship in the Department from 2016-21. Dr. Unadkat’s research interests are on mechanisms of transport and metabolism of drugs during pregnancy, and transport of drugs across the placental, hepatic, intestinal and blood-brain barrier.  Dr. Unadkat has published more than 250 peer-reviewed research papers.  He is a fellow of AAAS, AAPS, JSSX, and the founding co-chair (1999-2001) of the focus group of AAPS on Drug Transport and Uptake.  Dr. Unadkat received the AAPS Research Achievement Award in 2012 and the ISSX Scientific Achievement Award in 2023.  Dr.  Unadkat created and led the UW Research Affiliates Program on Transporters (UWRAPT), a cooperative effort between the UW School of Pharmacy and pharmaceutical companies, for 10 years. He also leads UWPKDAP, a NIDA funded Program Project grant (P01) on drug disposition during pregnancy and co-leads UW Transporter Elucidation Center (https://depts.washington.edu/uwtec/) funded by NICHD to identify and characterize novel transporters in the placenta and the developing intestine.  Dr. Unadkat has been an Associate Editor for the Journal of Pharmaceutical Sciences, an Editor of AAPS Journal, and a member of the NIH Pharmacology study section (2000-3).  Dr. Unadkat has organized or co-organized numerous national and international conferences on the role of transporters and pregnancy in the disposition of drugs.   

With over 25 years of experience in drug metabolism, Tashinga graduated with a BSc (Hons) Biochemistry and DPhil from the University of Zimbabwe followed by a postdoctoral fellowship at AstraZeneca, Sweden and research associateship at the Cancer Research Institute, University of Cambridge, UK. He is currently senior scientist in the Oncology DMPK Department at AstraZeneca Cambridge, UK and his role focuses on contributing to a deep understanding of the metabolism and disposition of the AstraZeneca oncology small molecule portfolio and some of this work is exemplified by the publications: Drug Metab Dispos 51:892–901, 2023 and Drug Metab Dispos 46:1268-1276, 2018.

Udoamaka (Amaka) Ezuruike is a Senior PBPK Consultant in the Consultancy team at Certara UK (Simcyp Division). She obtained a Pharmacy degree from the University of Benin in Nigeria, an MSc in Pharmacology from the University of Oxford and a PhD in Pharmaceutical Sciences from the School of Pharmacy, University College London for her research investigating pharmacokinetic herb-drug interactions amongst diabetic patients. She joined Simcyp in 2015 after completing her PhD and has been involved in the expansion of the capabilities of the Simcyp simulator, including the development and verification of population files and small molecule compound files, and the prediction of clinical drug-drug interactions.  She currently works directly with clients to develop and apply PBPK models to particular projects of interest.