A Phase 2 Study of JNT-517 in Adolescent Participants With Phenylketonuria (NCT06637514) | Clinical Trial Compass
CompletedPhase 2
A Phase 2 Study of JNT-517 in Adolescent Participants With Phenylketonuria
United States, Australia14 participantsStarted 2025-07-16
Plain-language summary
The goal of this Phase 2, randomized study is to assess the safety, tolerability, and pharmacokinetics (PK) of oral JNT-517 in adolescents (12 to less than 18 years of age) with PKU. Participants will receive either JNT-517 or placebo and will be blinded to their treatment assignment. Participants will have a 4 in 5 (or 80%) chance of receiving JNT-517. The study will last for up to 63 days including a Screening period, Treatment period and Follow-up period for safety.
Participants will:
* Take 75 mg JNT-517 or a placebo BID (2x per day) for 28 days
* Visit the clinic or have a mobile health nurse visit your home for checkups and tests
* Collect urine sample at home and bring to clinic on specified days
* Keep a food diary 3 days before each study visit
Who can participate
Age range
12 Years – 17 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Males and females 12 to less than 18 years of age, inclusive on Day 1.
. Clinical diagnosis of PKU.
. Ability to swallow tablets.
. Average of 2 plasma Phe levels during the Screening period greater than 360 μM and no plasma Phe level less than 300 μM.
. Body weight equal or greater than 45 kg and body mass index less than 40 kg/m2.
. Females of childbearing potential must practice sexual abstinence or agree to use 2 highly effective contraceptive methods.
. Capable of giving signed informed consent (emancipated minors) or parent/legal guardian to provide informed consent and the participant to give assent and confirm ability to comply with study procedures.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Number of participants with treatment-emergent adverse events (TEAEs)
Timeframe: Screening to Study Completion (Average of 9 weeks)
Trial details
NCT IDNCT06637514
SponsorOtsuka Pharmaceutical Development & Commercialization, Inc.
. Any acute or chronic medical condition that would prevent the participant from complying with the procedures or place the participant at risk if they participate in the study.
. Positive for hepatitis B or C or human immunodeficiency virus.
. Any history of malignancy in the last 5 years, excluding nonmelanoma skin cancer.
. Any history of liver disease.
. Any history of cataracts or more than minimal cataracts observed during the Screening ophthalmologic examination.
. Any surgical or medical conditions that may affect study drug absorption, distribution, metabolism, or excretion.
. Creatinine clearance less than 90 mL/min by Cockcroft-Gault formula.
. History of drug or alcohol abuse in the last year