A Long-Term Study of JNT-517 in Participants With Phenylketonuria

Trial statusRecruiting
Trial phasePhase 3
Trial typeInterventional
Biological sexAll
Age4+
SponsorOtsuka Pharmaceutical Development & Commercialization, Inc.

About this trial

The goal of this Phase 3, open-label study is to evaluate the long-term safety of JNT-517 in pediatric and adult participants with Phenylketonuria (PKU) after completion of either Study JNT517-101 (NCT05781399) or JNT517-201 (NCT06637514) as well as participants who have not participated in a prior JNT-517 study. In this trial, all participants will receive JNT-517 using age- and weight-banded dosing as outlined in the protocol, regardless of any dose received in a previous study.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Diagnosis of phenylketonuria (ie, PAH deficiency) by either molecular testing or biochemical criteria consistent with the applicable regional guidelines.

Participants 4 years of age and older, inclusive, at time of Screening.

Not on pegvaliase within 4 weeks of Screening.

Not on sepiapterin within 2 weeks of Screening.

Disqualifiers

Participation in this study is not considered safe and/or feasible in the opinion of the Investigator.

Participants have not completed a previous JNT-517 study and are eligible for another active JNT-517 trial at the site, unless approval is obtained from the medical monitor.

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.

Trial design

Design model

Single group

Treatments tested in this trial

  • JNT-517

    Drug

    JNT-517 administered orally twice daily using age- and weight-banded dosing.

Treatment groups

240 Participants
are divided into 1 treatment group
Group A: JNT-517Experimental treatment 1 intervention

Trial outcomes

Primary outcomes

1

Number of Participants with Treatment-emergent Adverse Events (TEAEs)

Reported based on results of 12-lead electrocardiograms (ECGs), vital signs, clinical laboratory tests, and other medical assessments.

Time frame
Screening to +2 weeks from last dose

Secondary outcomes

1

Absolute Change from Baseline in Plasma Phe

Time frame
Baseline to +2 weeks from last dose
2

Percent Change from Baseline Over Time in Plasma Phe

Time frame
Baseline to +2 weeks from last dose
3

Percentage of Participants with Plasma Phe <600 micromoles (µM) Over Time in Participants with Baseline Phe >600 µM

Time frame
Baseline to +2 weeks from last dose
4

Percentage of Participants with Plasma Phe ≤360 µM Over Time in Participants with Baseline Phe >360 µM

Time frame
Baseline to +2 weeks from last dose

Other outcomes

Sponsors and contacts

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