Also on Trial Friend:Phenylketonuria pageMatch Me
All 29 Phenylketonuria trials and their US sites
Enter your ZIP code above to sort them by how far their nearest open site is from you.
- A Long-term, Post-marketing Safety Study of Palynziq in Patients With PKU (PALace)Most sites in Colorado, Georgia and IllinoisRecruitingBioMarin Pharmaceutical12US sites
12 states - Immune Modulation During Palynziq® Treatment in Adults (IMPALA)Most sites in California, Colorado and FloridaRecruitingPhase 4Ages 18-65BioMarin Pharmaceutical12US sites
12 states - A Long Term, Post-marketing Study of Immune Response in Patients Receiving Palynziq Treatment for PKU (PALisade)Most sites in Colorado, Georgia and IllinoisRecruitingBioMarin Pharmaceutical11US sites
11 states - A Study of JNT-517 in Participants With Phenylketonuria (PKU)Most sites in Florida, Texas and CaliforniaRecruitingPhase 3Ages 4+Otsuka Pharmaceutical Development & Commercialization10US sites
8 states - A Long-Term Study of JNT-517 in Participants With PhenylketonuriaMost sites in Texas, Florida and OregonRecruitingPhase 3Ages 4+Otsuka Pharmaceutical Development & Commercialization8US sites
5 states - A Study of MZE782 in Adults With PKUMost sites in California, Illinois and IndianaRecruitingPhase 2Ages 18-75Maze Therapeutics7US sites
6 states - AAV Gene Therapy Clinical Study in Adult Classic PKU (PHEdom)Most sites in California, Minnesota and New JerseyRecruitingPhase 1/2Ages 18-55NGGT5US sites
5 states - A Study to Evaluate Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of AG-181 in Subjects With PhenylketonuriaMost sites in Indiana, Pennsylvania and TexasRecruitingPhase 1Ages 18-69Agios Pharmaceuticals3US sites
3 states - Nutritional Impacts of Palynziq on Patients With Phenylketonuria (PKU)Only in GeorgiaRecruitingAges 16+Emory University2US sites
- PheCheck™ Validation StudyMost sites in Illinois and MassachusettsRecruitingAges 1+Aptatek BioSciences2US sites
2 states - A Global, Multicenter Study to Assess Maternal, Fetal and Infant Outcomes of Exposure to Palynziq® (Pegvaliase) During Pregnancy and BreastfeedingOnly in North CarolinaRecruitingBioMarin Pharmaceutical1US site
- A Study of Sepiapterin in Participants With Phenylketonuria (PKU)Only in IndianaRecruitingPhase 3Up to age 9PTC Therapeutics1US site
- A Trial to Examine if Repinatrabit is Processed Differently in Adults With Reduced Liver or Kidney Function Compared to Adults With Normal Liver and Kidney FunctionOnly in FloridaRecruitingPhase 1Ages 18-65Otsuka Pharmaceutical Development & Commercialization1US site
- Development of Novel Psychological Assessment Tools and Anxiety Intervention for PhenylketonuriaOnly in MissouriRecruitingAges 10-17University of Missouri-Columbia1US site
- Educational, Social Support, and Nutritional Interventions and Their Cumulative Effect on Pregnancy Outcomes and Quality of Life in Teen and Adult Women With PhenylketonuriaOnly in GeorgiaRecruitingAges 11+Emory University1US site
- Impact of Phenylalanine Elevations on Brain and Cognition in Adult PKU CarriersOnly in MissouriRecruitingAges 18-60University of Missouri-Columbia1US site
- A Clinical Study on the Safety and Tolerability of PL54 Injection in Adult Patients With Phenylketonuria (PKU)RecruitingPhase 1Ages 18-55Chongqing Peg-Bio Biopharm Co.No US site yet
- Announcement of Rare Metabolic Diseases in Systematic Newborn Screening: the Phenylketonuria Experience.RecruitingAges 18+Assistance Publique - Hôpitaux de ParisNo US site yet
- Brain Aging in PhenylketonuriaRecruitingAges 18+Insel Gruppe AG, University Hospital BernNo US site yet
- Eating Disorders in Patients With PhenylketonuriaRecruitingCentral Hospital, Nancy, FranceNo US site yet
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Who runs the Phenylketonuria trials in the US, and what stage they are in
Of the 16 Phenylketonuria trials with a US site, 3 are in Phase 3, the last stage before a company can ask the FDA for approval. Earlier Phase 1 or 2 tests of safety and dosing make up 4 of them. One is a Phase 4 study of an already approved treatment. The remaining 8 have no drug phase, such as studies that follow people over time or test a device or a way of giving care. Companies run 12 of them, and universities, hospitals, foundations and government groups run 4. The sponsors with the most are BioMarin Pharmaceutical (4), Otsuka Pharmaceutical Development & Commercialization (3) and Emory University (2). The most recently listed one first appeared on ClinicalTrials.gov on July 20, 2026.
Phenylketonuria trials in the US, state by state
Of the 16 Phenylketonuria trials with a US site, 10 accept children under 18. Their open sites are in 16 states, most often Georgia, Illinois and Oregon. A trial counts once in each state where it has an open site, and some trials accept both children and adults.
Show the other 10 states
US hospitals running the most Phenylketonuria trials
Centers that run trials for a rare condition often see more people with it than most clinics do, so this list can also help you find doctors who know Phenylketonuria.
- Indiana University School of MedicineIndianapolis, Indiana4 trials
- Boston Children's HospitalBoston, Massachusetts3 trials
- Oregon Health and Science UniversityPortland, Oregon3 trials
- University of Pittsburgh Medical CenterPittsburgh, Pennsylvania3 trials
- University of Pittsburgh Medical Center (UPMC) - Children's Hospital of PittsburghPittsburgh, Pennsylvania3 trials
- Ann & Robert H. Lurie Children's Hospital of ChicagoChicago, Illinois2 trials
- Emory UniversityAtlanta, Georgia2 trials
- Northwestern UniversityChicago, Illinois2 trials
- University of ColoradoAurora, Colorado2 trials
- University of Florida (UF) Health Shands HospitalGainesville, Florida2 trials
Help getting to a Phenylketonuria trial far from home
Ask the study team whether the trial pays back travel, parking and hotel costs, because many sponsors do. The FDA's guidance on paying research volunteers says paying back these costs does not count as pressuring someone to join.
These nonprofits also help patients reach care, and each one sets its own rules.
- Mercy Medical Angels
- Pays for gas cards, ground rides and airline tickets anywhere in the US, and it lists clinical trials as a reason to travel. Household income at or below 300% of the federal poverty guidelines, and usually a trip of 50 miles or more each way.
- Air Charity Network
- Volunteer pilots in all 50 states fly patients for free in small private planes, and members also fly people taking part in clinical trials. You must be able to walk and sit upright for the flight, show financial need and have a backup plan if weather cancels it.
- Ronald McDonald House
- Gives families a room near the hospital while a child gets care, through 394 House programs around the world. Families of a sick child, with rules set by each local chapter.
- Healthcare Hospitality Network
- Keeps a map of hospitality houses near hospitals, and most member houses charge little or nothing to patients and families. Each house sets its own rules, so check with the house near your study site.
Program details were checked on each program's website on October 24, 2026.
Questions about finding a Phenylketonuria trial near you
Are there Phenylketonuria clinical trials near me?
As of November 13, 2026, 29 Phenylketonuria clinical trials are recruiting now and 5 are not yet recruiting. In the US, 16 of them have at least 1 open site, across 20 states. Enter your ZIP code on this page to rank every one of them by the distance to its closest open site, with the sites shown on a map.
Which states have Phenylketonuria clinical trial sites?
Recruiting Phenylketonuria trials list open sites in 20 states. Pennsylvania, Texas and Illinois have the most, and the table on this page lists every state.
Are there Phenylketonuria trials for children near me?
Of the 16 Phenylketonuria trials with a US site, 10 accept children under 18. Their open sites are in 16 states, most often Georgia, Illinois and Oregon. Each trial sets its own age limits, so check the ages listed on a trial before you contact it.
Who pays for travel to a Phenylketonuria clinical trial?
Many trial sponsors pay back travel, parking and hotel costs, so ask the study team before you rule out a far-away site. The FDA's guidance says paying back these costs does not count as pressuring someone to join. Charities such as Mercy Medical Angels and Air Charity Network can also help with rides and flights.
What if there is no Phenylketonuria trial near me?
Some trials send staff to your home or use a local lab, so fewer visits happen at the study site. You can also sign up on this page to get an email when a Phenylketonuria trial opens a new site or changes status.
How is the distance to a trial site measured?
Distances are straight-line miles from the center of your ZIP code to each study site's listed location, not driving distance. Your browser looks up the ZIP code's coordinates with a free map service, Zippopotam.us, and the ZIP code is never sent to or stored by Trial Friend.
FDA-approved for Phenylketonuria: Sephience (sepiapterin), Kuvan (sapropterin dihydrochloride), Palynziq (pegvaliase-pqpz).
Clinical trials near you for related conditions
Source: ClinicalTrials.gov, trials with status Recruiting or Not yet recruiting. Refreshed every 6 hours; counts as of November 13, 2026. Sites that ClinicalTrials.gov lists as closed or withdrawn are left out. Children means the trial's age group includes people under 18.