Medical Information Only. Consult your healthcare provider before considering clinical trial enrollment.
Urea Cycle Disorders: early-phase trial registry
2 of 5 indexed Urea Cycle Disorders trials are currently recruiting, with more weight in Phase 1-2.
Corpus placement: #3,391 of 28,707 conditions by registered trial count.
5 US clinical trials · 2 currently recruiting · #3,391 of 28,707 conditions by registered trial count
Urea Cycle Disorders: 5 US clinical trials tracked, 2 recruiting.
Urea Cycle Disorders is the subject of 5 registered US clinical trials on ClinicalTrials.gov, 2 of them currently open to new participants. 0 are in Phase 3-4 (later-stage) and 3 in Phase 1-2 (earlier-stage). The most active sponsor is Brendan Lee, running 1 of these trials.
Enrollment posture brief
Registry condition urea-cycle-disorders
OPEN 2 | RECR 40% | LATE 0 | EARLY 3 | RANK #3391 | SPON 1
Volume-matched condition peers
Nearest open-share peer: Achondroplasia (40% recruiting · 10 trials)
Urea Cycle Disorders lists 2 open slots (40% of 5 indexed trials). Peers are matched on registered volume, not therapeutic-area browse lists. How peer matching works →
Key findings
What ClinicalTrials.gov does not surface for Urea Cycle Disorders on its own pages , computed from the registry mirror as of 2026-08-08. Each line carries its own denominator so it can be quoted as it stands.
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Urea Cycle Disorders is recruiting below its size-band peers.
2 of 5 indexed trials (40%) are open to enrollment, against a 46.5% average across 27,806 conditions with fewer than 20 trials. The peer set uses the same ClinicalTrials.gov-derived counts as this page.
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One sponsor concentrates Urea Cycle Disorders research.
Brendan Lee accounts for 1 of 5 trials (20%). 5 distinct sponsors appear on at least one study for this condition label.
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Most Urea Cycle Disorders trials plan to enrol fewer than 100 people.
Median target enrolment is 14 among the 5 trials that report a genuine target (sentinel values excluded). 4 of those (80%) plan for fewer than 100 participants.
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Urea Cycle Disorders splits between interventional and observational designs.
3 interventional and 2 observational studies make up this index (60% interventional). Study type is sponsor-reported on ClinicalTrials.gov.
Open and recent trials
5 total, page 1 of 1
Longitudinal Study of Urea Cycle Disorders
Andrea Gropman
NCT00237315
Neuroimaging and Neuropsychological Outcomes in Urea Cycle Disorders
Children's National Research Institute
NCT02935283
Dose-Escalation Safety Study of HPN-100 to Treat Urea Cycle Disorders
Amgen
NCT00551200
Arginine and Buphenyl in Patients With Argininosuccinic Aciduria (ASA), a Urea Cycle Disorder
Brendan Lee
NCT00345605
Pilot Study For Hypothermia Treatment In Hyperammonemic Encephalopathy In Neonates And Very Young Infants
Uta Lichter-Konecki
NCT01624311
Phase Distribution
| Phase | Trial count |
|---|---|
| Phase 2 | 3 |
Top Sponsors
Named interventions
Most-linked intervention names on Urea Cycle Disorders records (sponsor-reported on ClinicalTrials.gov). Counts are trial links, not unique products.
US sites by state
Facility locations filed on Urea Cycle Disorders trials. A trial with sites in several states counts in each.
Source: ClinicalTrials.gov, National Library of Medicine. Data is informational only.
Related
What to do with this Urea Cycle Disorders page
5 registered trials, 2 currently recruiting, is a starting point for a conversation, not a diagnosis or a recommendation.
- 2 Urea Cycle Disorders trials are currently recruiting, check eligibility criteria before contacting a site. Browse recruiting trials
- Brendan Lee sponsors the most Urea Cycle Disorders trials on record, review their full trial history before evaluating a specific study. See Brendan Lee's trials
- Bring the specific trial ID (NCT number) to your own doctor before enrolling, this page is a directory, not medical guidance. Read the trial-finding guide
Trial and recruiting counts reflect ClinicalTrials.gov registry status as of the data vintage above; individual trial eligibility and enrollment status can change.
Every figure on PlainTrial is rendered directly from the ClinicalTrials.gov registry, no number is typed in by an editor. This Urea Cycle Disorders condition card totals 5 registered trials; most-linked intervention Sodium Phenylbutyrate; top US site state Texas. See our editorial standards & corrections policy, the methodology behind these numbers, the data changelog, or report a data error.