A Phase I/II Open-label Safety and Efficacy Study of LNP.UCD.ABE in Patients With Urea Cycle Diso… (NCT07667387) | Clinical Trial Compass
Not Yet RecruitingPhase 1/2
A Phase I/II Open-label Safety and Efficacy Study of LNP.UCD.ABE in Patients With Urea Cycle Disorders.
United States7 participantsStarted 2026-07
Plain-language summary
This is a single-site Phase 1/2 open-label umbrella clinical trial designed to evaluate the safety, tolerability, and efficacy of a single intravenous dose of LNP.UCD.ABE in 5 pediatric subjects with severe infantile-onset UCDs. This is a master clinical protocol in which subjects with a variant in a urea cycle disorder (UCD) gene (CPS1, OTC, ASS1, ASL, ARG, NAGS, or SLC25A15) that is demonstrated to be amenable to corrective editing by an adenine base editor (ABE) would be eligible for enrollment.
Who can participate
Age range
24 Hours – 5 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Diagnosis of a severe urea cycle disorder, in the judgement of the investigators;
. Molecular testing demonstrating homozygosity or compound heterozygosity for a disease-causing mutation in a urea cycle disorder gene (CPS1, OTC, ASS1, ASL, ARG, NAGS, or SLC25A15) that is targeted by a variant-specific version LNP.UCD.ABE;
. Current or historical biochemical testing consistent with a urea cycle disorder;
. At least one of the subject's alleles must be amenable to base editing by LNP.UCD.ABE, as assessed in vitro;
. A history of an ammonia level of ≥400 μmol/L prior to age 12 months, unless a diagnosis was made prenatally and care was initiated immediately after birth. If the patient is taking an ammonia scavenger medication, their ammonia level may currently be in the normal range. If the patient is diagnosed prenatally, then personal history, family history, or analysis of mutations should indicate a high likelihood of a severe UCD;
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Safety and tolerability of a single intravenous dose of LNP.UCD.ABE
. Subjects more than 8 weeks from the initial diagnosis of a severe UCD must have demonstrated a persistent need for dietary protein restriction and chronic administration of a nitrogen scavenger medication, and/or a recurrent hyperammonemic event, and/or a history of a hyperammonemic-induced seizure.
. Weight \>3.5 kg at the time of screening;
. Legal guardian(s) capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.
Exclusion criteria
. Abnormal liver function, electrolyte, coagulation, or blood count laboratory values thought not attributable to the underlying urea cycle disorder;
. Demonstrated need for urgent liver transplantation due to liver failure, in the opinion of the investigators;
. Participation in a prior gene therapy trial or participation in a trial of an investigational product in the last 12 months;
. History of liver transplantation;
. Any other diseases or conditions that the investigators would consider to pose unacceptable risk to the subject;
. Inability or unwillingness to comply with the visit schedule and study assessments;
. Any genetic variation in the causative urea cycle disorder gene that, in the opinion of the investigators, may decrease the potential efficacy of the drug product;
. History of severe hypersensitivity or anaphylaxis to polyethylene glycol (PEG)-containing products, such as PEG-containing vaccines or laxatives