title: Phase I clinical study of NMK36: a new PET tracer with the synthetic amino acid analogue anti-[18F]FACBC.
abstract: OBJECTIVE
  NMK36 is a novel PET tracer containing a synthetic amino acid analogue anti-[(18)F]FACBC as the active ingredient, and is under development for the use of tumor diagnosis. A Phase I clinical study of NMK36 was conducted to evaluate its safety, biodistribution, and radiation dosimetry in healthy volunteers.
  
  
  METHODS
  Six healthy volunteers (Japanese male) received a bolus injection of NMK36 (174.4-201.4 MBq) intravenously. The safety of NMK36 was evaluated by monitoring signs/symptoms, electrocardiography, recording vital signs, and laboratory examinations at baseline and several time points in 6 days after injection. A total of 11 whole-body PET-CT scans were acquired up to 4 h post-injection, and venous blood and urine samples were also collected for 6 and 24 h post-injection, respectively. Based on the results of the biodistribution study, absorbed radiation dose was estimated by the MIRD method.
  
  
  RESULTS
  Although two adverse events occurred after the injection of NMK36, they were mild and disappeared without any specific treatment. NMK36 preferentially accumulated in the pancreas and liver early after injection, followed by rapid clearance from the pancreas. Persistent uptake was observed in the skeletal muscle. NMK36 showed low uptake in the brain, and its urinary excretion was limited (5.40 ± 1.43% of the injected dose at 24 h post-injection). The liver was the critical organ, with a mean absorbed dose of 40.6 μGy/MBq. The estimated effective dose of NMK36 was 13.8 μSv/MBq, which was similar to or lower than those of radiotracers approved for clinical use including [(18)F]FDG.
  
  
  CONCLUSIONS
  The findings of this study indicate that NMK36 is well tolerated. NMK36 has favorable characteristics for imaging brain and pelvic tumors, such as low brain uptake, slow urinary excretion, and high in vivo stability.
authors.affiliation: Department of Radiology and Radiation Oncology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Asano
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Inoue
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Kei
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Hara
authors.forename: Chikako
authors.initials: C
authors.lastname: Taguchi
authors.forename: Takanori
authors.initials: T
authors.lastname: Tokushige
authors.forename: Hideki
authors.initials: H
authors.lastname: Maruo
authors.forename: Tohoru
authors.initials: T
authors.lastname: Takeda
authors.forename: Tomomi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Tomoe
authors.initials: T
authors.lastname: Fujita
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kumagai
authors.forename: Kazushige
authors.initials: K
authors.lastname: Hayakawa
mesh_terms: D000596:Amino Acids / Q000009:adverse effects / Q000737:chemistry* / Q000493:pharmacokinetics; D002264:Carboxylic Acids / Q000737:chemistry*; D003503:Cyclobutanes / Q000009:adverse effects / Q000737:chemistry* / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D049268:Positron-Emission Tomography / Q000379:methods*; D011849:Radioactive Tracers; D011874:Radiometry; D012449:Safety; D055815:Young Adult
chemical_list: D000596:Amino Acids; D002264:Carboxylic Acids; D003503:Cyclobutanes; D011849:Radioactive Tracers; C117460:fluciclovine F-18