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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
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
A Study to Evaluate the Safety and Efficacy of JNT-517 in Participants With Phenylketonuria (PKU)
Otsuka Pharmaceutical Development & Commercialization
NCT06971731
A Study of Sepiapterin in Participants With Phenylketonuria (PKU)
PTC Therapeutics
NCT06302348
Rapid Drug Desensitization Study in Adults Experiencing Hypersensitivity Reactions to Palynziq
BioMarin Pharmaceutical
NCT06780332
A Long-Term Safety Study of PTC923 in Participants With Phenylketonuria
PTC Therapeutics
NCT05166161
First-in-Human, Multiple Part Clinical Study of JNT-517 in Healthy Participants and in Participants With Phenylketonuria
Otsuka Pharmaceutical Development & Commercialization
NCT05781399
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
Safety and Therapeutic Effects of Sapropterin Dihydrochloride on Neuropsychiatric Symptoms in Phenylketonuria (PKU) Patients
BioMarin Pharmaceutical
NCT01114737
Effect of Kuvan on Neurocognitive Function, Blood Phenylalanine Level, Safety, and Pharmacokinetics in Children With PKU
BioMarin Pharmaceutical
NCT00838435
A Phase 1 Study to Evaluate Effects of Sapropterin Dihydrochloride on QTc Intervals in Healthy Adult Subjects
BioMarin Pharmaceutical
NCT00789568
Sapropterin in Individuals With Phenylketonuria
Washington University School of Medicine
NCT00730080
A Study to Evaluate Subcutaneously Administered rAvPAL-PEG in Patients With Phenylketonuria for 24 Weeks
BioMarin Pharmaceutical
NCT01560286
The Effectiveness of Kuvan in Amish PKU Patients
University Hospitals Cleveland Medical Center
NCT02677870
Phase Distribution
| Phase | Trial count |
|---|---|
| Phase 1 | 3 |
| Phase 2 | 1 |
| Phase 3 | 5 |
| Phase 4 | 2 |
Top Sponsors
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.
Read our methodology — how this data is sourced, computed, and verified.
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.