Urea Cycle Disorders, Inborn clinical trials
The registry lists 66 studies for Urea Cycle Disorders, Inborn across more than 10 countries. 14 are recruiting or about to start. 48 of them are mainly about Urea Cycle Disorders, Inborn (how this is decided). Per ClinicalTrials.gov, last updated 2026-11-05. Counting its narrower condition Ornithine Carbamoyltransferase Deficiency Disease too: 104 studies, 23 open.
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Who runs them
Amgen (10) · Baylor College of Medicine (6) · Cellaion SA (4) · Cytonet GmbH & Co. KG (4) · Children's National Research Institute (3) · National Center for Research Resources (NCRR) (2) · Ultragenyx Pharmaceutical Inc (2) · Kaleido Biosciences (2)
What is being tested here
Drugs under test in Urea Cycle Disorders, Inborn studies, those with the most open studies first. Medicines only given beside them are not counted. How drugs are counted
| Drug | Open | Phase 3 | All |
|---|---|---|---|
| Glycerol phenylbutyrate | 0 | 3 | 9 |
| Phenylbutyric acid | 0 | 1 | 4 |
| Sodium Benzoate | 0 | 0 | 2 |
| Arginine | 0 | 0 | 1 |
| Bentonite | 0 | 0 | 1 |
| Carglumic acid | 0 | 0 | 1 |
Coming up
Studies recruiting or running, from their records. “Main data collection” ends at the primary completion date, the sponsor’s own estimate, which often moves.
All 3
- Dec 2026Liver Disease in Urea Cycle Disorders · Baylor College of Medicine
- Jul 2027At Home Ammonia Monitoring of Inborn Errors of Ammonia Metabolism · Sequitur Health Corp.
- Aug 2027Phase 1/2 Study of KRRO-121 in Healthy Volunteers and Patients With UCD · Korro Bio, Inc.
Who these studies take
Of the 12 Urea Cycle Disorders, Inborn studies recruiting now, 5 (42%) set no upper age limit and 7 (58%) stop at 75 or younger. 11 (92%) take children under 18. 0 (0%) are for women only and 0 (0%) for men only; 4 (33%) take healthy volunteers.
| Age | Women | Men |
|---|---|---|
| 10 | 7 (58%) | 7 (58%) |
| 18 | 10 (83%) | 10 (83%) |
| 30 | 8 (67%) | 8 (67%) |
| 40 | 8 (67%) | 8 (67%) |
| 50 | 7 (58%) | 7 (58%) |
| 65 | 6 (50%) | 6 (50%) |
| 75 | 5 (42%) | 5 (42%) |
| 85 | 5 (42%) | 5 (42%) |
Across all 66 studies, recruiting or not: 65% stop at 75 or younger and 61% at 65; 73% take children; 0% are for women only and 2% for men only; 30% take healthy volunteers. From each study’s registry entry; the criteria on its page decide.
What changed recently
From the registry's own updates since Oct 14, 2026.
Newly registered1
- MENA/Levant Epidemiological, Registry of Immunological & Clinical Traits (MERIT)Oct 23, 2026NCT07892651
Studies
Recruiting first, then most recently updated. Showing 50 of 66. Browse all 66 → or search them.
- Long-term Follow-up (LTFU) Study of Participants in Any iECURE Protocol Using an Investigational Product (IP)RecruitingNCT068056953 countries
- MENA/Levant Epidemiological, Registry of Immunological & Clinical Traits (MERIT)Not yet recruitingNCT078926511 country
- Phase 1/2 Study of KRRO-121 in Healthy Volunteers and Patients With UCDRecruitingNCT07773246Phase 1/21 country
- Study of LNP.UCD.ABE in Patients With Urea Cycle DisordersRecruitingNCT07667387Phase 1/21 country
- Functional Evaluation in Patients With Urea Cycle Disorders (UCD) During a Driving TaskRecruitingNCT077016941 country
- At Home Ammonia Monitoring of Inborn Errors of Ammonia MetabolismRecruitingNCT06953505Not applicable1 country
- A Clinical Study of Glycerol Phenylbutyrate in Chinese Patients With Urea Cycle DisordersRecruitingNCT069040271 country
- Ureagenesis Analysis in Healthy Subjects and in Urea Cycle Disorder PatientsRecruitingNCT05671666Not applicable1 country
- Hepatic Histopathology in Urea Cycle DisordersRecruitingNCT049083191 country
- MyRareDiet A Novel Diet Tracking ToolNot yet recruitingNCT06664840Not applicable
- Neuroimaging and Neuropsychological Outcomes in Urea Cycle DisordersRecruitingNCT029352831 country
- Longitudinal Study of Urea Cycle DisordersRecruitingNCT002373154 countries
- Systemic Biomarkers of Brain Injury From HyperammonemiaRecruitingNCT046023251 country
- Orphan Europe Carbaglu® Surveillance ProtocolRecruitingNCT034090031 country
- An Open-label Study to Investigate ECUR-506 in Male Babies Less Than 9 Months of Age With Neonatal Onset OTC DeficiencyActive, not recruitingNCT06255782Phase 34 countries
- Long Term Follow Up to Evaluate DTX301 in Adults With Late-Onset OTC DeficiencyActive, not recruitingNCT036364385 countries
- Dysregulated Urea-synthesis at Terminal UremiaCompletedNCT05076318Not applicable1 country
- Liver Disease in Urea Cycle DisordersActive, not recruitingNCT046127641 country
- Study of CMP-CPS-001 in Healthy Volunteers and Participants With Abnormal Heterozygous OTC GenotypeActive, not recruitingNCT06247670Phase 12 countries
- To Evaluate the Safety of Long-term Use of HPN-100 in the Management of Urea Cycle Disorders (UCDs)CompletedNCT01257737Phase 42 countries
- Study of the Safety and Tolerability of HPN-100 Compared to Sodium Phenylbutyrate in Children With Urea Cycle DisordersCompletedNCT00947544Phase 22 countries
- Study of the Safety, Pharmacokinetics and Efficacy of HPN-100, in Pediatric Subjects With Urea Cycle Disorders (UCDs)CompletedNCT01347073Phase 31 country
- Dose-Escalation Safety Study of HPN-100 to Treat Urea Cycle DisordersCompletedNCT00551200Phase 21 country
- Study of the Safety of HPN (Hyperion)-100 for the Long-Term Treatment of Urea Cycle Disorders (Treat UCD)CompletedNCT00947297Phase 32 countries
- Efficacy and Safety of HPN-100 for the Treatment of Adults With Urea Cycle DisordersCompletedNCT00992459Phase 32 countries
- Study of Glycerol Phenylbutyrate & Sodium Phenylbutyrate in Phenylbutyrate Naïve Patients With Urea Cycle Disorders (UCDs)CompletedNCT03335488Phase 44 countries
- A Study of the Safety, Efficacy and Pharmacokinetics of Glycerol Phenylbutyrate in Pediatric Subjects Under 2 Years of Age With Urea Cycle DisordersCompletedNCT02246218Phase 42 countries
- Observational Study That Will Collect Information on Patients With Urea Cycle Disorders (UCDs)TerminatedNCT019484271 country
- A Study of Glyceryl Tri-(4-phenylbutyrate) Administered Orally as a Single Dose, and Twice Daily for Seven Consecutive Days to Subjects With Hepatic Impairment With Cirrhosis and to a Control GroupCompletedNCT00986895Phase 11 country
- HepaStem Long-Term Safety RegistryTerminatedNCT033437565 countries
- Characterization of Intestinal Microbiota in Children With Inborn Errors of Metabolism (IEM)CompletedNCT053300391 country
- Th1, Th2, Th17 Phenotype in Urea Cycle DisordersCompletedNCT057067141 country
- Nitric Oxide Supplementation on Neurocognitive Functions in Patients With ASLDCompletedNCT03064048Not applicable1 country
- Chronic Liver Disease in Urea Cycle DisordersCompletedNCT037213671 country
- Safety and Dose-Finding Study of DTX301 (scAAV8OTC) in Adults With Late-Onset Ornithine Transcarbamylase (OTC) DeficiencyCompletedNCT02991144Phase 1/24 countries
- Hepatocyte Transplantation for Liver Based Metabolic DisordersTerminatedNCT01345578Phase 11 country
- UNLOCKED: A Phase 2, Open-label Trial With KB195 in Subjects With a Urea Cycle DisorderTerminatedNCT03933410Phase 27 countries
- Manipulating the Gut Microbiome StudyTerminatedNCT03181828Phase 1/21 country
- A Collection of Case Studies in Infants With UCD to Evaluate Infant Growth and the Safety of a New Medical Food for UCDCompletedNCT03911089Not applicable1 country
- Safety and Tolerability of SYNB1020-CP-001CompletedNCT03179878Phase 11 country
- PCORI Urea Cycle Disorder StudyCompletedNCT027401531 country
- A Safety and Efficacy Study of Infusions of HepaStem in Urea Cycle Disorders Pediatric PatientsWithdrawnNCT03884959Phase 21 country
- Patient and Observer Reported Outcome Measurements in Inborn Errors of MetabolismCompletedNCT042480621 country
- Safety Study of HepaStem for the Treatment of Urea Cycle Disorders (UCD) and Crigler-Najjar Syndrome (CN)CompletedNCT01765283Phase 1/25 countries
- Study to Evaluate the Efficacy of HepaStem in Urea Cycle Disorders Paediatric Patients (HEP002)CompletedNCT02489292Phase 24 countries
- Nitric Oxide Supplementation in Argininosuccinic AciduriaCompletedNCT02252770Not applicable1 country
- Clinical Food Study to Evaluate the Effect of KB195 on Gut Nitrogen Metabolism in Patients With Urea Cycle DisordersCompletedNCT03797131Not applicable1 country
- The NIH UNI Study: Urea Cycle Disorders, Nutrition and ImmunityTerminatedNCT014218881 country
- Safety, Tolerability and PK/PD Evaluation of Intravenous Administration of MRT5201 in Patients With OTC DeficiencyWithdrawnNCT03767270Phase 1/2
- Long-term Safety Follow-up Study of Patients Having Received HepaStem (SAF001)CompletedNCT020510491 country