JNT-517 for Adults with PKU
This Phase 3 study is testing JNT-517, an investigational oral treatment for adults with PKU. The official study record currently does not yet show a Canadian site, but CanPKU+ has independently verified recruitment at the M.A.G.I.C. Clinic in Calgary.
Study overview
Official study title: A Phase 3, Double-Blind, Randomized, Two-Period, Multicenter, Placebo-Controlled, Efficacy and Safety Study of JNT-517 for the Treatment of Participants With Phenylketonuria
Condition: Phenylketonuria (PKU)
Intervention / therapy: JNT-517 tablets compared with placebo
Sponsor: Otsuka Pharmaceutical Development & Commercialization, Inc.
Study phase: Phase 3
ClinicalTrials.gov ID: NCT06971731
Last checked by CanPKU+: March 10, 2026
If you notice that this information is out of date, please let us know at website@canpku.org.
Who may qualify
According to the official study record, this study is for adults 18 years of age and older with PKU. The study includes a screening period to confirm dietary stabilization and amino acid levels needed for eligibility.
Important: Final eligibility is always determined by the study team.
Canadian site information
Current CanPKU+ classification: Recruiting in Canada
Canadian site listed on ClinicalTrials.gov: Not yet listed at the time of review
Independently verified Canadian recruitment site:
M.A.G.I.C. Clinic
Suite 102, 6715 - 8 Street NE
Calgary, Alberta T2E 7H7
Phone: 587-885-3076
For sites outside Canada: Please use the official ClinicalTrials.gov record below for the most current list of locations.
Therapy background and related studies
JNT-517, also referred to in Otsuka materials as repinatrabit, is an investigational oral small-molecule treatment being studied for PKU.
Otsuka announced the initiation of this global Phase 3 trial in December 2025.
This study is designed to assess safety, efficacy, tolerability, and pharmacokinetics in adults with PKU.
Official study record and links
For the most current status, full site list, and eligibility details, use the official study record.
Development history and publications
This section highlights earlier studies and publications related to this treatment program. It is intended as a plain-language research history summary and does not replace the official study record.
Earlier and related studies in this program
Phase 1/2 study: First-in-Human, Multiple Part Clinical Study of JNT-517 in Healthy Participants and in Participants With Phenylketonuria
ClinicalTrials.gov ID: NCT05781399
This earlier study evaluated safety, tolerability, pharmacokinetics, and formulation characteristics of JNT-517 in healthy participants and in participants with PKU.
Current Phase 3 study: A Study to Evaluate the Safety and Efficacy of JNT-517 in Participants With Phenylketonuria
ClinicalTrials.gov ID: NCT06971731
This is the current randomized Phase 3 study in adults with PKU.
Long-term extension study: A Study to Evaluate the Long-Term Safety and Efficacy of JNT-517 in Participants With Phenylketonuria
ClinicalTrials.gov ID: NCT06628128
This extension study is designed for participants who complete earlier JNT-517 studies, including JNT517-101 or JNT517-201.
Publications and scientific presentations to date
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Harding C, Longo N, Viader A, et al. O01: Efficacy and safety outcomes of JNT-517, a first-in-class SLC6A19 inhibitor, in adults with phenylketonuria: A randomized study.
Read publication / abstract -
Otsuka announcement on initiation of the global Phase 3 repinatrabit (JNT-517) trial, including reference to earlier Phase 1/2 data presented at SSIEM 2024.
Read company announcement -
Sponsor study page for the Phase 3 program.
View sponsor study page
If you notice that this section is missing a publication or no longer reflects the latest study history, please let us know at website@canpku.org.