A Study of JNT-517 in Participants With Phenylketonuria (PKU)

Otsuka

Status and phase: Enrolling; Phase 3

Conditions: Phenylketonuria

Treatments: Drug: JNT-517 Matching Placebo; Drug: JNT-517

Study type: Interventional

Funder types: Industry

Identifiers

NCT06971731

2024-519554-37-00 (EU Trial (CTIS) Number)

1011258 (Other Identifier)

JNT517-301

Details and patient eligibility

About

This Phase 3 study will evaluate the safety, effectiveness, tolerability, and how the body processes JNT-517 in children, adolescents, and adults with phenylketonuria.

Participants will be randomly assigned to receive either JNT-517 or placebo during an initial 6-week treatment period. After this period, eligible participants will receive JNT-517 for an additional 46 weeks.

Enrollment: 120 estimated patients

Sex: All

Ages: 4+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Male or female participants aged 4 years or older.
2. Diagnosed with phenylketonuria.
3. Have phenylalanine levels that meet study requirements.
4. Meet study-specific requirements regarding current treatment for phenylketonuria.
5. Willing and able to follow study dietary requirements.
6. Weigh at least 12.5 kilograms.
7. If able to become pregnant or father a child, willing to follow the study's contraception requirements.
8. Any ongoing mental health condition must be stable before entering the study.
9. Able to provide informed consent (or have consent provided by a parent or legal guardian, when applicable) and comply with study procedures.

Exclusion criteria

Participants will be excluded from the study if any of the following criteria are met:

1. Significant medical condition that, in the investigator's opinion, could make participation unsafe or interfere with study participation.
2. Significant liver disease or impaired kidney function.
3. Certain eye conditions, including significant cataracts.
4. Active infection requiring medical evaluation.
5. History of certain cancers within the past 5 years.
6. Allergy or hypersensitivity to JNT-517 or its ingredients.
7. Prior treatment with JNT-517.
8. Recent participation in another investigational study or receipt of an investigational treatment that does not meet study requirements.
9. Use of medications that are not permitted during the study.
10. Abnormal laboratory or heart test results that would make study participation inappropriate.
11. Conditions that could affect the absorption of oral study medication.
12. History of recent substance or alcohol abuse.
13. Unwillingness to follow study requirements, including restrictions on intentional weight loss.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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120 participants in 3 patient groups, including a placebo group

JNT-517 - High Dose

Experimental group

Description:

Participants will receive JNT-517 orally, twice daily (BID), with dosing determined by age, for 6 weeks in Period 1, followed by JNT-517 orally, BID for 46 weeks in Period 2.

Treatment:

Drug: JNT-517

JNT-517 - Low Dose

Experimental group

Description:

Participants will receive JNT-517 orally, BID, with dosing determined by age, for 6 weeks in Period 1, followed by JNT-517 orally for 46 weeks in Period 2.

Treatment:

Drug: JNT-517

Placebo

Placebo Comparator group

Description:

Participants will receive JNT-517 matching placebo orally, BID for 6 weeks in Period 1, followed by JNT-517 orally, BID for 46 weeks in Period 2.

Treatment:

Drug: JNT-517 Matching Placebo