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ClinicalTrials.gov 4 recruiting now official registry

Phenylketonuria clinical trials

Every US clinical trial registered for Phenylketonuria — phase mix, recruiting status, and the sponsors running them, straight from the NIH ClinicalTrials.gov registry.

13 US clinical trials · 4 currently recruiting

The research picture

Phenylketonuria has 13 registered US clinical trials, 4 of them open to new participants right now — about 31% of the total.

4
recruiting participants now
31%
of trials open to enrollment
7
in Phase 3–4 (later-stage)
5
top sponsor: BioMarin Pharmaceutical

Counts reflect the public ClinicalTrials.gov registry as last mirrored by PlainTrial. Status and phase are reported by each study's sponsor. This is reference information, not medical advice.

Active & Recent Trials

RECRUITING NA 200 participants

Educational, Social Support, and Nutritional Interventions and Their Cumulative Effect on Pregnancy Outcomes and Quality of Life in Teen and Adult Women With Phenylketonuria

Emory University

NCT01659749

RECRUITING Phase 3 120 participants

A Study to Evaluate the Safety and Efficacy of JNT-517 in Participants With Phenylketonuria (PKU)

Otsuka Pharmaceutical Development & Commercialization

NCT06971731

RECRUITING Phase 3 56 participants

A Study of Sepiapterin in Participants With Phenylketonuria (PKU)

PTC Therapeutics

NCT06302348

RECRUITING Phase 4 10 participants

Rapid Drug Desensitization Study in Adults Experiencing Hypersensitivity Reactions to Palynziq

BioMarin Pharmaceutical

NCT06780332

ACTIVE NOT RECRUITING Phase 3 200 participants

A Long-Term Safety Study of PTC923 in Participants With Phenylketonuria

PTC Therapeutics

NCT05166161

ACTIVE NOT RECRUITING Phase 1 135 participants

First-in-Human, Multiple Part Clinical Study of JNT-517 in Healthy Participants and in Participants With Phenylketonuria

Otsuka Pharmaceutical Development & Commercialization

NCT05781399

ACTIVE NOT RECRUITING Phase 1 32 participants

A Phase 1/Phase 2 Open-label Study to Evaluate the Safety, Tolerability, and Efficacy of a Single Intravenous Administration of SAR444836 in Adult Participants With Phenylketonuria

Sanofi

NCT05972629

COMPLETED Phase 3 206 participants

Safety and Therapeutic Effects of Sapropterin Dihydrochloride on Neuropsychiatric Symptoms in Phenylketonuria (PKU) Patients

BioMarin Pharmaceutical

NCT01114737

COMPLETED Phase 3 95 participants

Effect of Kuvan on Neurocognitive Function, Blood Phenylalanine Level, Safety, and Pharmacokinetics in Children With PKU

BioMarin Pharmaceutical

NCT00838435

COMPLETED Phase 1 56 participants

A Phase 1 Study to Evaluate Effects of Sapropterin Dihydrochloride on QTc Intervals in Healthy Adult Subjects

BioMarin Pharmaceutical

NCT00789568

COMPLETED 45 participants

Sapropterin in Individuals With Phenylketonuria

Washington University School of Medicine

NCT00730080

COMPLETED Phase 2 24 participants

A Study to Evaluate Subcutaneously Administered rAvPAL-PEG in Patients With Phenylketonuria for 24 Weeks

BioMarin Pharmaceutical

NCT01560286

COMPLETED Phase 4 7 participants

The Effectiveness of Kuvan in Amish PKU Patients

University Hospitals Cleveland Medical Center

NCT02677870

Phase Distribution

PhaseTrial count
Phase 1 3
Phase 2 1
Phase 3 5
Phase 4 2

Source: ClinicalTrials.gov, National Library of Medicine. Data is informational only.

Reading the Phenylketonuria Trial Landscape

ClinicalTrials.gov lists 13 US studies indexed under Phenylketonuria, and 4 of those are currently open to recruitment — roughly 31% of the total volume on the registry. That ratio is a useful proxy for activity level: a high share of recruiting studies often signals that research interest is current and that new enrollment opportunities are appearing, while a low share typically means the field is dominated by completed or follow-up work where most participant spots have already been filled. These counts reflect the public registry only and include studies at every stage of design, so they should be read as an index of research attention rather than as a measure of treatment availability.

The phase distribution for Phenylketonuria shows 7 late-stage studies (Phase 3 and Phase 4 combined) alongside 4 earlier-phase entries (Phase 1 through Phase 2). Phase 1 and Phase 2 studies focus on early safety signals, dosing, and preliminary effect, while Phase 3 studies are typically the larger efficacy and safety trials submitted toward regulatory review, and Phase 4 studies follow approved interventions in real-world use. A condition weighted toward later phases often reflects a mature research pipeline with several interventions already close to or past approval, whereas a heavier early-phase tilt suggests the field is still exploring new mechanisms and candidate approaches.

Top sponsor activity for Phenylketonuria is led by BioMarin Pharmaceutical with 5 indexed trials, alongside 6 other organizations in the top contributor list. The list on this page surfaces up to 13 of the most relevant recent and active entries, ordered with recruiting studies first so practical options are visible. All figures are derived from the public ClinicalTrials.gov dataset maintained by the National Library of Medicine and are reproduced here for reference. Inclusion of a trial, sponsor, or intervention on this page is neither an endorsement nor a recommendation — eligibility, protocol changes, and site-level status can shift frequently, so always verify current details on ClinicalTrials.gov and consult a qualified healthcare provider before acting on anything you see here.

Frequently Asked Questions

How many clinical trials are there for Phenylketonuria?

PlainTrial tracks 13 US clinical trials for Phenylketonuria, of which 4 are currently recruiting participants. Data sourced from ClinicalTrials.gov.

How do I find a recruiting trial for Phenylketonuria?

Use the trial list above filtered by "Recruiting" status, or visit our trial finder at /recruiting to search by condition and state. Always discuss trial participation with your healthcare provider before enrolling.

Is this data current?

Data is sourced from ClinicalTrials.gov and reflects our most recent data pull. Trial status may have changed since then. Always verify current information at ClinicalTrials.gov before making decisions about participation.

Related

Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from ClinicalTrials.gov (National Library of Medicine). Consult a qualified professional before making decisions based on this data.

Source: ClinicalTrials.gov (NIH/NLM) ClinicalTrials.gov AACT registry · 2026 Trial counts and statuses sourced from ClinicalTrials.gov. Sponsor counts include both industry and federal/academic sponsors.

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