A Phase 3 interventional study of Pegtibatinase and Placebo in Homocystinuria, sponsored by Travere Therapeutics, Inc.. Recruiting at 52 sites in 14 countries. Open to participants aged 12 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-11-09.
Sponsored by Travere Therapeutics, Inc. · Phase 3, Interventional, and Treatment
Researchers are looking for a better way to treat people living with classical homocystinuria (HCU), a rare inherited condition. It is caused by changes in the cystathionine beta-synthase (or "CBS") gene and prevents an enzyme from working correctly in the body. This enzyme helps break down homocysteine, which is produced when the body processes methionine from protein-containing foods. This helps keep homocysteine and methionine at healthy levels. When this enzyme is not working, homocysteine and methionine build up in the blood and then spread into different tissues of the body and stop these body tissues from working normally.
People living with HCU can experience problems with their vision, bones, blood vessels, thinking, learning, and memory. Available treatments for HCU include a low-methionine diet (typically achieved by limiting protein-containing foods), a methionine-free protein supplement to help meet daily protein needs, and betaine (Cystadane®). These treatments are either not sufficient or are hard to take for many patients.
Pegtibatinase was designed by researchers to act like the CBS enzyme, which is missing or not working properly in people living with HCU. Researchers are studying whether adding pegtibatinase to standard treatment can lower homocysteine levels.
Researchers want to learn how safe and effective pegtibatinase is, how it moves through and affects the body, and how it may affect the daily lives of people with HCU.
The study plans to enroll participants from the US, Australia, Belgium, France, Germany, Ireland, Italy, Poland, Portugal, Qatar, Saudi Arabia, Spain, Turkey, and the United Kingdom. Many study visits may happen at home, depending on where you live and local regulations. Some visits may include a home nurse and telemedicine appointments with the study doctor.
Primary Objective:
Researchers want to learn more about how pegtibatinase will affect homocysteine and methionine levels when it is injected under the skin in participants already receiving standard treatment.
Blood tests will be used to measure changes in these levels during the study.
Secondary Objectives:
Researchers also want to learn:
Study Population and Treatments:
This is a global study will include children and adults from 12 to 65 years old. Participants in the study will take their standard of care treatment. Participants will be put into 1 of 2 groups at random (like the flip of a coin) to take either:
Study Duration and Visits:
Participants may be in the study for up to 38 weeks, including the screening period of up to 4 weeks, a pre-treatment period of up to 6 weeks where the participants will discuss their current diet with a dietitian (a health professional specialized in nutrition), a blinded treatment period of up to 24 weeks, and a safety follow-up visit completed 4 weeks after the last dose of study medication. Participants who complete the blinded treatment period may qualify to join the ENSEMBLE study before finishing the safety follow-up visit.
Participants who meet all study requirements may have up to 58 study visits. Visits may take place at a study center, at home, or by telemedicine.
These visits can include:
Safety / Adverse Events:
Researchers will monitor participants for any medical problems that occur during the study. Participants will have regular laboratory tests, health checkups, and study visits to monitor their health and safety.
Benefit-risk Conclusion:
Researchers have worked to reduce risks to participants in this study. They believe the risks of taking pegtibatinase in this study are justified by the potential benefits that they think pegtibatinase may have for people with HCU.
20 studies on the registry are indexed under Homocystinuria; 5 are open to participants now.
This study's planned enrollment of 70 is above the median of 22 across 12 interventional studies indexed under Homocystinuria.
Browse Homocystinuria studies →Travere Therapeutics, Inc. is the lead sponsor of 14 studies on the registry; 4 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 4 (80%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Drug: Pegtibatinase
Other: Placebo
Pegtibatinase BIW
Also known as: OT-058, TVT-058
volume-matched saline SC BIW
Change from baseline in plasma tHcy levels - Weeks 6 to 12
Change between baseline and average of 6 to 12 week (6, 8, 10, and 12 week) plasma tHcy levels in participants receiving pegtibatinase vs. placebo. Baseline tHcy level defined as average of Week -3, Week -1, and Day 1 pre-dose plasma tHcy
Time frame: Weeks 6 - 12
Change from baseline in plasma tHcy levels - Weeks 16 to 24
Change between baseline and average of 16 to 24 week (16, 20, and 24 week) plasma tHcy levels in participants receiving pegtibatinase vs. placebo. Baseline tHcy level defined as average of Week -3, Week -1, and Day 1 pre-dose plasma tHcy
Time frame: Weeks 16 - 24
Plan to share: Yes — Requests for clinical trial data, including language stating its intended use, should be directed to datarequest@travere.com. If approved, the requested information will be provided to the requestor after signing a data access agreement. Requests can be made following completion of the study and full publication of the study data in a peer reviewed journal for up to 36 months following its publication. Travere reserves the right to decline or recommend modifications to a request if it does not comply with the data sharing policy or if it is determined that the request is made by a biased source.
Time frame: Requests can be made following completion of the study and full publication of the study data in a peer reviewed journal for up to 36 months following its publication.
Access criteria: Requires submission and approval of intended use and a data sharing agreement.
No publications or documents are linked to this record.
Started Dec 2023 (actual). Primary completion is estimated for Aug 2027, 44 months after the start.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Pegtibatinase
Travere Therapeutics, Inc.