A Phase 2 Study of JNT-517 in Adolescent Participants With Phenylketonuria

Eligibility Criteria

• 1. Males and females 12 to less than 18 years of age, inclusive on Day 1.
• 2. Clinical diagnosis of PKU.
• 3. Ability to swallow tablets.
• 4. Average of 2 plasma Phe levels during the Screening period greater than 360 μM and no plasma Phe level less than 300 μM.
• 5. Body weight equal or greater than 45 kg and body mass index less than 40 kg/m2.
• 6. Females of childbearing potential must practice sexual abstinence or agree to use 2 highly effective contraceptive methods.
• 7. 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.
• 1. 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.
• 2. Positive for hepatitis B or C or human immunodeficiency virus.
• 3. Any history of malignancy in the last 5 years, excluding nonmelanoma skin cancer.
• 4. Any history of liver disease.
• 5. Any history of cataracts or more than minimal cataracts observed during the Screening ophthalmologic examination.
• 6. Any surgical or medical conditions that may affect study drug absorption, distribution, metabolism, or excretion.
• 7. Creatinine clearance less than 90 mL/min by Cockcroft-Gault formula.
• 8. History of drug or alcohol abuse in the last year
• 9. Current, recent, or suspected infection within 14 days of Screening of SARS CoV 2/COVID 19.
• 10. Participation in another investigational drug trial within 30 days or, if known 5 half-lives of investigational drug (whichever is longer).
• 11. Unable to tolerate oral medication.
• 12. Allergy to JNT-517 or any component of the investigational product.
• 13. Received greater than 50 mL of blood or plasma within 30 days of Screening or greater than 500 mL of blood or plasma within 60 days of Screening.