Research of promotion and Support Headquarters

Takenao Koseki

  (古関 竹直)

Profile Information

Affiliation
Professor, Department of Regulatory Science for Evaluation and Development of Pharmaceuticals and Devices, Fujita Health University School of Medical Sciences, Fujita Health University
Degree
博士(薬学)

Researcher number
70850551
ORCID ID
 https://orcid.org/0000-0002-2889-9586
J-GLOBAL ID
202001007661048523
researchmap Member ID
R000007329

Awards

 5

Papers

 42
  • Takenao Koseki, Masashi Kondo, Hidetsugu Fujigaki, Kayoko Kikuchi, Yuko Oya, Hiroshi Kato, Tomohiro Mizuno, Naotake Tsuboi, Kenji Kawada, Yasuhiro Goto, Naozumi Hashimoto, Kazuyoshi Imaizumi, Akiko Kada, Hikaru Yabuuchi, Kuniaki Saito, Hideyuki Saya
    JMIR research protocols, Jan 20, 2026  Lead authorCorresponding author
    BACKGROUND: Cisplatin-induced nephrotoxicity (CIN) is a major dose-limiting adverse event that can lead to both acute and chronic kidney injury. The formation of thiol-cisplatin conjugates within renal tubular cells has been implicated as a key mechanism underlying CIN. Flopropione is an inhibitor of cysteine conjugate β-lyase 1, an enzyme that catalyzes the formation of the thiol-cisplatin conjugate, which might prevent CIN. OBJECTIVE: We designed a clinical trial to evaluate the safety of flopropione in patients receiving cisplatin-based chemotherapy and explore its efficacy in preventing CIN. METHODS: This is a phase I/IIa, single-center, randomized, open-label trial conducted in patients undergoing cisplatin therapy. Participants are randomized at a 5:2 ratio per cohort to receive either flopropione or no treatment. On the day of cisplatin administration, the flopropione group receives oral flopropione twice daily (80 mg in Cohort 1, 160 mg in Cohort 2, and 240 mg in Cohort 3). On the following day, all cohorts receive three doses of 80 mg of oral flopropione. A step-up dose escalation design is adopted, progressing from Cohort 1 to 3 after confirming safety at each level. The primary endpoint is the safety of flopropione use in combination with cisplatin; the secondary endpoints include changes in the levels of urinary biomarkers of nephrotoxicity, such as neutrophil gelatinase-associated lipocalin, liver-type fatty acid-binding protein, and kidney injury molecule-1. Blood and urine samples are collected within 48 h before cisplatin administration and at 24 h, 48 h, and 1 week after its initiation for safety and efficacy assessments. RESULTS: The first participant was registered in July 2024. As of the date of manuscript submission in November 2025, participant registration is ongoing. The final participant will complete the study by March 2026. Publication of results is expected by March 2027. CONCLUSIONS: This study is expected to contribute to advances in preventive strategies for CIN by providing evidence that inhibition of cysteine conjugate β-lyase 1 by flopropione may attenuate CIN. CLINICALTRIAL: Japan Registry of Clinical Trials jRCTs041220021; https://jrct.mhlw.go.jp/en-latest-detail/jRCTs041220021.
  • Takahiro Kato, Tomohiro Mizuno, Takenao Koseki, Kazuo Takahashi, Shigeki Yamada, Kazuyoshi Imaizumi, Naotake Tsuboi, Naozumi Hashimoto
    Fujita medical journal, 11(3) 129-134, Aug, 2025  
    OBJECTIVES: Sivelestat sodium hydrate (SSH) may be effective in the early stage of acute respiratory distress syndrome (ARDS) before the neutrophil extracellular trap scaffold structure is complete. Therefore, patients with suppression of fibrinolysis (SF) before the secondary fibrinolytic process might benefit from SSH administration. The primary aim of this study was to determine the effect of the SF state and combination therapy on the effect of SSH administration. METHODS: We retrospectively reviewed the data of patients diagnosed with ARDS at Fujita Health University Hospital between July 2005 and December 2016. Patients with ARDS were stratified into the SF and hyperfibrinolysis (HF) groups. Using the fibrin degradation product (FDP)/D-dimer ratio, cut-off values were set as follows: FDP/D-dimer >2 for the HF group and FDP/D-dimer ≤2 for the SF group. The 28-day mortality was the primary endpoint. RESULTS: In total, 168 patients (71 in the HF group and 97 in the SF group) were included in the analysis. The mortality within 28 days was not different based on SSH administration in either group (HF group: p=0.956, SF group: p=0.957). In the SF group, the mortality rate within 28 days in SSH-treated patients who received antithrombotic drugs was significantly higher than that in patients who received SSH only (p<0.05). However, this finding was not present in the HF group (p=0.786). CONCLUSIONS: Concomitant use of SSH and antithrombotic drugs might worsen the treatment outcome of patients with ADRS in the SF state.
  • Hitoshi Iwasaki, Hiroshi Kato, Takenao Koseki, Masashi Kondo, Shigeki Yamada
    Journal of pharmaceutical health care and sciences, 11(1) 54-54, Jul 1, 2025  Lead authorCorresponding author
  • TAKAKI KANIE, TOMOHIRO MIZUNO, TAKENAO KOSEKI, AYA HANAMOTO, HIROKO SAWANO, MASAKO TOMIDA, YUKIKO KAKUMAE, TAKAHIRO HAYASHI, HIROSHI MATSUOKA, MASANOBU USUI, SHIGEKI YAMADA
    In Vivo, 39(3) 1647-1653, Apr 28, 2025  
  • Masaya Takahashi, Katsuyuki Takahashi, Kanae Takahashi, Daichiro Fujiwara, Kaori Ito, Hirotake Yamase, Kaito Yamashiro, Hajime Asano, Naoki Yabuta, Tadafumi Hoshida, Takenao Koseki, Masahito Shibano, Kanako Tsukada, Yasuhiko Takata, Yuika Komatsu, Satoshi Noda, Kohei Hashimoto, Toru Otori
    Scientific Reports, 15(1), Mar 21, 2025  

Research Projects

 3

Other

 6