Newsletter Volume 41, Number 1, 2026

CoRTIS -Corporate Rising Talents Initiative Session- Behind the Scenes of the Event

The 4th CoRTIS Executive Committee

　The 4th CoRTIS was held during the 40th Annual Meeting of the Japanese Society of Pharmacokinetics.

　CoRTIS stands for Corporate Rising Talents Initiative Session, a program designed primarily for young researchers engaged in pharmacokinetic research within companies and other organizations to foster exchange and mutual growth.

　This article reveals everything from the background of CoRTIS’s establishment to its future outlook, including behind-the-scenes details known only to the executive committee! … (To be continued on the NL homepage / Members Only)

Challenges in Predicting Gastrointestinal Toxicity Using Small Intestinal Organoids

Department of Molecular Pharmacokinetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo
Yoshiki Hashimoto

　My name is Yoshiki Hashimoto from the Graduate School of Pharmaceutical Sciences, The University of Tokyo. I am grateful to the editorial committee and all involved for this opportunity to contribute to the Japanese Society of Pharmacokinetics Newsletter, “NEW POWER in Pharmacokinetic Research.”

　I joined the Department of Molecular Pharmacokinetics at the Graduate School of Pharmaceutical Sciences, The University of Tokyo, in my fourth year of undergraduate studies in 2019. I have been conducting research under the guidance of Professor Hiroyuki Kusunohara and Professor Kazuya Maeda (currently at Kitasato University).I obtained my doctoral degree in March 2025 and assumed the position of Specially Appointed Assistant Professor in the same department in April of the same year. While my research environment remains unchanged, my role has shifted from student to faculty member. Currently, in my first year as a faculty member, I am engaging in research and education through daily trial and error. … (To be continued on the NL homepage / Members Only)

Part 2: Examples of microphysiological system applications in drug discovery

Translational & Biomedical Science, Astellas Pharma Inc.
Maho Okubo

　Hello, everyone! In this series, “The Latest Research Infrastructure Supporting Drug Discovery and Development Research,” we are covering microphysiological systems (MPS) over three installments. In Part 1, as an introduction to this series, Takama from our company outlined the definition, characteristics, and importance of MPS, including related terminology (if you haven’t read it yet, please refer to Part 1).In that article, we identified the lack of case sharing among companies regarding each model as one of the bottlenecks hindering MPS adoption. Therefore, in this second installment, we will introduce several examples of how MPS is actually being utilized in drug discovery settings. We hope this information will be useful for researchers considering introducing MPS. … (To be continued on the NL homepage / Members Only)

Receiving the Best Poster Award

Department of Medical Informatics and Pharmacy, Graduate School of Pharmaceutical Sciences, Kumamoto University
Issei Fujita

　I am deeply honored to have received the Best Poster Award at the 40th Annual Meeting of the Japanese Society of Pharmacokinetics. I extend my sincere gratitude to the judges and all members of the society. This paper describes the awarded topic: “Expression Variations of Pharmacokinetic Control Factors and Involvement of Parathyroid Hormone-Related Proteins in Cancer Cachexia.”

　Cachexia is a metabolic syndrome observed in more than half of patients with advanced cancer, contributing to poor prognosis and discontinuation of chemotherapy. Although reduced clearance of CYP substrate drugs has been reported during cancer cachexia, the detailed mechanism remains unclear. … (To be continued at the NL website)

Receiving the Best Poster Award

Tokyo University of Pharmacy and Life Sciences, Department of Pharmacokinetics and Drug Delivery
Misato Kunieda

　It is a great honor to receive the prestigious Best Poster Award at the 40th Annual Meeting of the Japanese Society for Pharmacokinetics for our poster titled “Functional identification of MCT7 as a novel drug resistance transporter in breast cancer cells.” We extend our deepest gratitude to the judges and all members of the Japanese Society for Pharmacokinetics.

　Monocarboxylate transporter 7 (MCT7) belongs to a transporter family involved in the efflux transport of monocarboxylic acids, including lactate. MCT7 is highly expressed not only in normal tissues such as the human brain and liver but also in cancerous tissues like breast cancer and malignant melanoma. Its increased expression has been reported in human ovarian cancer cells that have developed resistance to certain anticancer drugs. … (To be continued at the NL website)

Receiving the Best Poster Award

Kanazawa University Graduate School of Pharmaceutical Sciences, Department of Drug Discovery Science, Laboratory of Drug Metabolism and Safety
Kyoka Nagaoka

　It is a great honor to have received the Best Poster Award at the 40th Annual Meeting of the Japanese Society for Pharmacokinetics for the poster titled “Stress granules formed via liquid-liquid phase separation sequester pregnane X receptor and suppress its downstream gene expression.” I would like to express my sincere gratitude to the judges and everyone who engaged in meaningful discussions.

　Liquid–Liquid Phase Separation (LLPS) is known to perform diverse physiological functions, such as gene expression regulation and stress responses, by transiently compartmentalizing nucleic acids and proteins within cells.This study aimed to clarify whether stress granules (SGs), one of the structures formed by LLPS, regulate the expression of drug-metabolizing enzymes, and further elucidate the molecular mechanism involved. … (To be continued at the NL website)

Receiving the Best Poster Award

Tokyo University of Pharmacy and Life Sciences, Department of Pharmacokinetics and Drug Delivery
Naoki Saito

　It is a great honor to receive the prestigious Best Poster Award at the 40th Annual Meeting of the Japanese Society of Pharmacokinetics. I extend my deepest gratitude to Professor Tomoyoshi Yamashita, the meeting chair, and all members of the Japanese Society of Pharmacokinetics.

　Antibody-drug conjugates (ADCs) have brought about a major paradigm shift in cancer treatment as a therapeutic modality that achieves both “high cytotoxic efficacy and low systemic toxicity,” something conventional chemotherapeutic drugs could not accomplish. To appropriately evaluate the efficacy and safety of ADCs, a detailed understanding of their mechanism of action based on their in vivo pharmacokinetic profile is essential.However, a current challenge is the inability to accurately isolate and evaluate multiple pharmacokinetic parameters affecting ADC efficacy as individual processes. … (To be continued at the NL website)

Receiving the Best Poster Award

Kumamoto University Graduate School, Department of Pharmaceutical Sciences, Division of Microbial Pharmacy
Yasuki Sasaki

　It is a great honor to receive the prestigious Best Poster Award at the 40th Annual Meeting of the Japanese Society of Pharmacokinetics. I would like to take this opportunity to express my sincere gratitude to the selection committee members and all related parties who reviewed this work.

　Enhancing the blood-brain barrier (BBB) permeability of monoclonal antibodies (mAbs) is a critical challenge in developing therapeutics for central nervous system disorders. In previous studies, we demonstrated that fusing the 7-amino acid cyclic peptide SLSHSPQ (SLS peptide), which possesses BBB permeability, to the C-terminus of the heavy chain of mAbs improves the antibody’s brain penetration.However, the activity of the SLS peptide requires the maintenance of its cyclic structure via disulfide bonds, and it was previously thought that controlling this structure was difficult using conventional C-terminal fusion methods. … (To be continued at the NL website)

Receiving the Best Poster Award

Otsuka Pharmaceutical Co., Ltd., Tokushima Drug Discovery Research Center, Preclinical Research Institute, Pharmacokinetics Research Department
Yasuhiro Sawai

　I am deeply honored to have received the Best Poster Award at the 40th Annual Meeting of the Japanese Society of Pharmacokinetics for my presentation titled “Method Development of Using Oxidative Reaction by Porphyrin for Structure Determination of Drug Metabolites.” I extend my heartfelt gratitude to the selection committee members and all those involved in the society.

　Traditionally, determining the structure of metabolites has involved sequentially synthesizing the most likely candidates and confirming their match with the target metabolite. However, this approach becomes extremely burdensome in terms of time, effort, and cost when numerous candidates are anticipated.Therefore, we developed a “direct oxidation method” using porphyrin, the active site of P450, to obtain metabolites through a chemical oxidation reaction mimicking in vivo metabolism. We evaluated this method using gefitinib as a substrate. … (To be continued at the NL website)

Receiving the Best Poster Award

Kanazawa University Graduate School of Medical and Pharmaceutical Sciences, Department of Drug Discovery Science, Laboratory of Drug Metabolism and Safety
Yusei Tahara

　It is a great honor to have received the Best Poster Award at the 40th Annual Meeting of the Japanese Society of Pharmacokinetics for the presentation titled “Protective role of protoporphyrin IX in acetaminophen-induced liver injury via suppression of ferroptosis.” We sincerely thank the judges and all those who engaged in meaningful discussions.

　Ferroptosis is a form of cell death induced by lipid peroxidation dependent on ferrous iron (^Fe2+), and it has been reported to be involved in various diseases and adverse drug reactions. Recently, the involvement of ferroptosis in acetaminophen (APAP)-induced liver injury has also been demonstrated, but the fundamental mechanism causing the elevation of ^Fe2+ remains unclear.Therefore, in ^{this study} , we focused on protoporphyrin IX (Protoporphyrin IX: PpIX), which is taken up and converted to heme, as a factor that suppresses ^Fe2+elevation. … (To be continued at the NL website)

Receiving the Best Poster Award

Japan Tobacco Inc. (now Shionogi & Co., Ltd.), Pharmacokinetics Research Institute
Hiroaki Takubo

　I am deeply honored to receive the Best Poster Award for my presentation titled “Utilization of endogenous biomarker 4β-hydroxycholesterol for quantitative prediction of CYP3A induction-mediated drug-drug interactions.” I extend my sincere gratitude to the judging committee members and all those involved with the Japanese Society of Pharmacokinetics.

　Since CYP3A is involved in the metabolism of many pharmaceuticals, early identification of its drug-drug interaction (DDI) risk is critically important. Guidelines for DDI testing cite the biomarker approach as one new method for assessing DDI risk.However, no specific criteria, such as judgment standards, are provided for the plasma 4β-hydroxy cholesterol/cholesterol ratio (4β-HC/C), known as a biomarker for CYP3A induction. … (To be continued at the NL website)

Receiving the Best Poster Award

Hokkaido University of Science, Faculty of Pharmaceutical Sciences, Department of Pharmaceutical Sciences
Kohei Togami

　At the 40th Annual Meeting of the Japanese Society of Pharmacokinetics, I was honored to receive the Best Poster Award (Applied Research Category) for my presentation titled “Intrapulmonary delivery of pirfenidone-loaded succinylated gelatin-coated liposomes improves pharmacokinetics and antifibrotic effects in fibrotic lungs.”I extend my deepest gratitude to Professor Tomoyoshi Yamashita, the Annual Meeting Chair, the members of the selection committee who evaluated my work, and all members of the Japanese Society of Pharmacokinetics. I am deeply honored.

　Pulmonary fibrosis, a representative example of interstitial lung disease, particularly idiopathic pulmonary fibrosis (IPF) of unknown cause, is a refractory disease with a poor prognosis. It causes honeycomb lungs due to severe fibrosis of lung tissue, significantly impacting quality of life through reduced respiratory function and ultimately leading to death.In Japan, two antifibrotic drugs, pirfenidone and nintedanib, are currently approved and clinically used for IPF treatment. However, it is not uncommon for patients to require dose reduction or discontinuation due to the occurrence of side effects. … (To be continued at the NL website)

Receiving the Best Poster Award

Toppan Holdings Co., Ltd. Research Institute
Yasuyuki Naito

　It is a great honor to receive the prestigious Best Poster Award at the 40th Annual Meeting of the Japanese Society of Pharmacokinetics for our presentation titled “An Engineered 3D Liver Tissue Model ( ^invivoid® ) for Long-Term Culture Without Medium Exchange.” We extend our deepest gratitude to the judging committee members and all those involved with the Japanese Society of Pharmacokinetics.

　In pharmaceutical safety assessment, establishing evaluation systems that accurately predict drug metabolism in the human liver remains a critical challenge. Conventional two-dimensional culture methods struggle to maintain the drug-metabolizing activity of hepatocytes, suggesting they cannot sufficiently replicate the behavior of test compounds during long-term exposure.Furthermore, regarding animal testing, based on the 3Rs principle (Replacement, Reduction, and Refinement), efforts to strictly limit and reduce its use are accelerating globally. Initiatives to replace animal experiments through the utilization of New Approach Methodologies (NAMs) are gaining momentum. … (To be continued at the NL website)

Receiving the Best Poster Award

Daiichi Sankyo Co., Ltd. Pharmacokinetics Research Institute
Miki Yokoyama

　It is a great honor to receive the Best Poster Award at the 40th Annual Meeting of the Japanese Society of Pharmacokinetics for the poster titled “Impact of degradation in subcutaneous tissue and lymphatic fluid on absorption of Fc-fusion proteins following subcutaneous administration.” We extend our sincere gratitude to the selection committee members and all those associated with the Japanese Society of Pharmacokinetics.

　Subcutaneous administration is widely used as a clinical route for biopharmaceuticals; however, factors affecting bioavailability (BA) after subcutaneous administration remain incompletely understood. This study focused on the impact of degradation in subcutaneous tissue and lymphatic fluid on the subcutaneous absorption of Fc-fusion proteins.For four types of Fc-fusion proteins, we developed two types of ligand-binding assays: (1) an Fc/Fc assay recognizing only the Fc portion, and (2) a Protein/Fc assay recognizing structures including the target binding site. We then verified the impact of degradation after subcutaneous administration on BA. … (To be continued at the NL website)

Receiving the Best Oral Presentation Award

Global Pharmacokinetics Research Department, Eisai Co., Ltd.
Saki Izumi

　It is a great honor to receive the Best Oral Presentation Award at the 40th Annual Meeting of the Japanese Society of Pharmacokinetics. I would like to express my heartfelt gratitude to Professor Tomoyoshi Yamashita, the Annual Meeting Chair, the selection committee members, and all those involved with the society.

　At this conference, we presented research findings on Coproporphyrin I (CP-I), a biomarker for OATP1Bs, titled “Impact of CP-I precursors on the evaluation of OATP1B-mediated drug–drug interactions based on CP-I concentrations in monkeys.”We demonstrated that human and monkey plasma contain CP-I precursors at levels over ten times higher than CP-I itself. These precursors readily oxidize in plasma to form CP-I, revealing that the values traditionally reported as “CP-I” actually originate from these precursors.Furthermore, in studies using monkeys, we demonstrated that quantifying pure CP-I after removing the precursor enables more sensitive detection of drug-drug interactions mediated by OATP1Bs. This sensitivity difference stems from substrate-dependent inhibition and variations in the contribution rate of OATP1B in the elimination pathway. … (To be continued at the NL website)

Receiving the Best Oral Presentation Award

Kitasato University, Department of Pharmaceutical Sciences
Shota Fukada

　It is a great honor to receive the Best Oral Presentation Award at the 40th Annual Meeting of the Japanese Society of Pharmacokinetics. I would like to express my heartfelt gratitude to Professor Tomoyoshi Yamashita, the conference chair, for his efforts in organizing this meeting, to the selection committee members who evaluated the presentations, and to all members of the Japanese Society of Pharmacokinetics.

　At this conference, I presented on the topic: “Quantitative evaluation of the cell-surface mucin layer thickness in goblet cell-enriched human intestinal epithelial cells for assessment of drug-induced gastrointestinal toxicity.” Nonsteroidal anti-inflammatory drugs (NSAIDs) possess excellent anti-inflammatory and analgesic effects, but are also known to cause dose-dependent gastrointestinal toxicity.Although mucosal protectants are often used concomitantly in clinical practice to counteract this gastrointestinal toxicity, adequate in vitro evaluation systems capable of appropriately assessing their toxicity and efficacy remain insufficiently established. … (To be continued at the NL website)

Received the Best Oral Presentation Award

BIKEN Next-Generation Vaccine Collaborative Research Center, Institute for Microbial Diseases, Osaka University Institute for Interdisciplinary Research
Toshiro Hirai

　It is a great honor to receive the Best Oral Presentation Award at the 40th Annual Meeting of the Japanese Society for Pharmacokinetics for the presentation titled “Hypertonic intranasal vaccines gain nasal epithelia access to exert strong immunogenicity.” I extend my deepest gratitude to the judges and all members of the Japanese Society for Pharmacokinetics.

　Nasal vaccines, administered via spray or droplets into the nose, are expected to strongly induce antibodies and T cells at the site of administration—the upper respiratory tract. Consequently, they are anticipated to efficiently prevent infection by respiratory viruses that initially infect the upper respiratory tract, offering high efficacy not only in preventing severe illness in individuals but also in controlling the spread of infection within society.However, the upper respiratory tract contains a mucosal barrier composed of mucus and cilia. This barrier inhibits the systemic absorption of nasally administered vaccines and their contact with cells, presenting a major obstacle to immune induction by nasal vaccines. … (To be continued at the NL website)

Receiving the Best Oral Presentation Award

Tokyo University of Science, Institute of Advanced Research, Institute for Intractable Diseases, Human Mimicry Systems Science Division
Fuki Yokoi

　I am honored to have received the Best Oral Presentation Award at the 40th Annual Meeting of the Japanese Society of Pharmacokinetics for my presentation titled “Establishment of a screening system using intestinal organoids for the development of therapeutics for inflammatory bowel disease.” I extend my deepest gratitude to the judges and all members of the Japanese Society of Pharmacokinetics.

　Inflammatory bowel disease (IBD) is a refractory disorder characterized by chronic inflammation in the intestine accompanied by erosions and ulcers. Achieving mucosal healing is considered a crucial therapeutic goal for IBD, as patients who attain it generally have a favorable prognosis. However, some patients fail to achieve mucosal healing with existing IBD treatments.Therefore, we established a phenotypic screening system incorporating human pluripotent stem cell-derived intestinal organoids and intestinal microphysiological systems (MPS). Using intestinal organoids, we identified compounds capable of suppressing inflammatory responses and reducing intestinal epithelial markers from a library of compounds, including Food and Drug Administration (FDA)-approved drugs. … (To be continued at the NL website)