Homocystinuria Due to CBS DeficiencyNCT02998710
Natural History Study of Homocystinuria Caused by Cystathionine Beta-Synthase Deficiency (ACAPPELLA)
An observational study of Homocystinuria Due to CBS Deficiency, run by Travere Therapeutics, Inc. at 11 sites in 4 countries.
Trial summary
The purpose of the study is to characterize the clinical course of homocystinuria in pediatric and adult patients aged 1 to 65 years under current clinical management practices Read more about this study
- Who is it for?
- Ages 1 year to 65 years
- Conditions the study is for
- Homocystinuria Due to CBS Deficiency
- How many people
- 110 participants
- Where
- 11 sitesin 4 countries
- Study dates
- Jan 2017to 31 Jul 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 1 year to 65 years
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: Clinical site
Who may be able to join
- Patients who are clinically diagnosed with homocystinuria
- Male/female patients aged 1 to 65 years
- Patients who consented and/or assented
- Patients who are willing and able to comply with all study-related procedures.
Who cannot join
- Medically significant postnatal complications or congenital anomalies that are not associated with homocystinuria
- Received any experimental therapy for homocystinuria during the 6 months prior to enrollment or expected to receive any such therapy during duration of the study
Trial locations and contacts
11 sites in 4 countries.
11 sites in 4 countries
United States7 sites
Emory University Hospital
Atlanta, Georgia, 30322
The Children's Hospital of Colorado
Aurora, Colorado, 80045
Boston Children's Hospital
Boston, Massachusetts, 02115
Indiana University School of Medicine
Indianapolis, Indiana, 46202
Science 37 - Virtual Site for the US and Canada
Morrisville, North Carolina, 27560
The Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, 19104
Children's National Hospital
Washington D.C., District of Columbia, 20010
United Kingdom1 site
Salford Royal NHS Foundation Trust
Salford, Manchester, M6 8HD
About this study
Official title: A Multicenter, Observational, Prospective, Natural History Study of Homocystinuria Due to Cystathionine Beta-synthase Deficiency in Pediatric and Adult Patients (ACAPPELLA)
The purpose of the study is to characterize the clinical course of homocystinuria in pediatric and adult patients aged 1 to 65 years under current clinical management practices
- Conditions
- Homocystinuria Due to CBS Deficiency
- Medical subject headings
- Homocystinuria
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in Met cycle metabolites levels - tHcy
Changes in total homocysteine levels in micromoles. The met cycle metabolites levels and change from baseline will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Changes in Met cycle metabolites levels - total Cys
Changes in total cysteine levels in micromoles. The met cycle metabolites levels and change from baseline will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Changes in Met cycle metabolites levels - Met
Changes in total methionine levels in micromoles. The met cycle metabolites levels and change from baseline will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Changes in Met cycle metabolites levels - Cth
Changes in total cystathionine levels in micromoles. The met cycle metabolites levels and change from baseline will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Patient Reported Outcome (PRO): Quality of Life in Neurological Disorders [Neuro-QoL]
Short forms for four domains (anxiety, depression, social activities, cognition function) by adults version for age 18+ and pediatric version for age 12-17 are used. A summary score will be calculated for each domain by adding up the scores for individual questions. The aggregated score for each domain as a continuous variable, and the change from baseline in the aggregated domain score will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Patient Reported Outcome (PRO): Quality of Life by 36-Item Short Form Survey [SF-36]
The original responses to all questions are scored on a scale from 0 to 100, with 100 representing the highest level possible. The rescaled scores that address each specific area of functional health status are averaged together, for a final score within each of the 8 domains measured. The average is based on the number of items with non-missing scores. The average score for each domain and the change from baseline will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
National Institutes of Health (NIH) Toolbox Cognition Battery
The NIH Toolbox is a multi-dimensional assessment tool that is used to measure the neurological and behavioral function of a patient over time. Assessments are recorded as 7 individual test scores, 1 total summary score and 2 composite scores. The raw measure scores and age-corrected standard scores and the change from baseline of the scores will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
EuroQol EQ-5D™ questionnaire to measure health and quality-of-life
EQ-5D™ is a standardized questionnaire as judged by the patients. This questionnaire consists of two parts:
- Five domains: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension consists of 5 levels of grading: no problem, slight problem, moderate problem, severe problem and extreme problem. For youths, 3 levels of grading: no problem, some problems, and a lot of problems.
- Visual analogue scale (VAS) is a vertical scale from 0 (worst) to 100 (best). Descriptive statistics will be provided for the five domains. Descriptive statistics will be provided for VAS and change from baseline at each visit for pooled EQ-5D-Y version and EQ-5D-5L version.
Measured: 6.5 years
Dual-Energy X-Ray Absorptiometry to measure bone mineral density
The z-score, t-score, and bone mineral density and change from baseline will be summarized by the location of X-ray (spine, hip, and total body) at each visit.
Measured: 6.5 years
Eye assessments to evaluate ocular health: Visual acuity examination will be performed to determine the clarity or sharpness of vision
Visual acuity examination will be performed to determine the clarity or sharpness of vision. The results will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Eye assessments to evaluate ocular health: Slit lamp eye examination will be performed to look for any diseases or abnormalities in the anterior portion of the eye
Slit lamp eye examination will be performed to look for any diseases or abnormalities in the anterior portion of the eye. The results will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Secondary outcomes (7)
Growth and development: World Health Organization (WHO) growth charts will be used to document height in centimeters (cm) for age 1 to 19 years old. Routine methods will be used to document height for all other age groups.
The results will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Growth and development: World Health Organization (WHO) growth charts will be used to document Body Mass Index (BMI) in kilograms per meter square for age 1 to 19 years old. Routine methods will be used to document BMI for all other age groups.
The results will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Growth and development: World Health Organization (WHO) growth charts will be used to document weight in kilograms (kg) for age 1 to 19 years old. Routine methods will be used to document weight for all other age groups.
The results will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Changes in alanine aminotransferase (ALT)
The results will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Changes in aspartate aminotransferase (AST)
The results will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Changes in alkaline phosphatase (ALP)
The results will be summarized using descriptive statistics at each visit.
Measured: 6.5 years
Optional homocystinuria genetic testing
Measured: The optional test will be done once at screening visit
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Dec 2016 (estimated)
- Study startJan 2017
- Primary completion31 Jul 2026
- Study completion31 Jul 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Homocystinuria Due to CBS DeficiencyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Prospective
- Enrolment
- 110 participants (actual)
Sponsor and investigators
- Lead sponsor
- Travere Therapeutics, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Michael Imperiale, MD, Study director, Travere Therapeutics, Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02998710
- Sponsor's protocol ID
- CBS-HCY-NHS-01
- Status last verified
- Aug 2026
- First submitted
- 2 Dec 2016
- Last updated
- 9 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- 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.
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Multicenter, Observational, Prospective, Natural History Study of Homocystinuria Due to Cystathionine Beta-synthase Deficiency in Pediatric and Adult Patients (ACAPPELLA)
- ClinicalTrials.gov ID
- NCT02998710
- Acronym / sponsor ID
- CBS-HCY-NHS-01
- Conditions
- Homocystinuria Due to CBS Deficiency
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 110 participants (actual)
- Lead sponsor
- Travere Therapeutics, Inc.Industry (pharma, biotech, devices)
- Study start
- Jan 2017 (actual)
- Primary completion
- 31 Jul 2026 (actual)
- Study completion
- 31 Jul 2026 (actual)
- First posted
- 20 Dec 2016 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of the study is to characterize the clinical course of homocystinuria in pediatric and adult patients aged 1 to 65 years under current clinical management practices
Study design
- Observational model
- Case only
- Time perspective
- Prospective
Who may qualify
- Ages
- 1 year to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Clinical site
Key inclusion criteria (4 listed)
- Patients who are clinically diagnosed with homocystinuria
- Male/female patients aged 1 to 65 years
- Patients who consented and/or assented
- Patients who are willing and able to comply with all study-related procedures.
Key exclusion criteria (2 listed)
- Medically significant postnatal complications or congenital anomalies that are not associated with homocystinuria
- Received any experimental therapy for homocystinuria during the 6 months prior to enrollment or expected to receive any such therapy during duration of the study
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Changes in Met cycle metabolites levels - tHcy
Time frame: 6.5 years
Changes in total homocysteine levels in micromoles. The met cycle metabolites levels and change from baseline will be summarized using descriptive statistics at each visit.
Changes in Met cycle metabolites levels - total Cys
Time frame: 6.5 years
Changes in total cysteine levels in micromoles. The met cycle metabolites levels and change from baseline will be summarized using descriptive statistics at each visit.
Changes in Met cycle metabolites levels - Met
Time frame: 6.5 years
Changes in total methionine levels in micromoles. The met cycle metabolites levels and change from baseline will be summarized using descriptive statistics at each visit.
Changes in Met cycle metabolites levels - Cth
Time frame: 6.5 years
Changes in total cystathionine levels in micromoles. The met cycle metabolites levels and change from baseline will be summarized using descriptive statistics at each visit.
Patient Reported Outcome (PRO): Quality of Life in Neurological Disorders [Neuro-QoL]
Time frame: 6.5 years
Short forms for four domains (anxiety, depression, social activities, cognition function) by adults version for age 18+ and pediatric version for age 12-17 are used. A summary score will be calculated for each domain by adding up the scores for individual questions. The aggregated score for each domain as a continuous variable, and the change from baseline in the aggregated domain score will be summarized using descriptive statistics at each visit.
Patient Reported Outcome (PRO): Quality of Life by 36-Item Short Form Survey [SF-36]
Time frame: 6.5 years
The original responses to all questions are scored on a scale from 0 to 100, with 100 representing the highest level possible. The rescaled scores that address each specific area of functional health status are averaged together, for a final score within each of the 8 domains measured. The average is based on the number of items with non-missing scores. The average score for each domain and the change from baseline will be summarized using descriptive statistics at each visit.
National Institutes of Health (NIH) Toolbox Cognition Battery
Time frame: 6.5 years
The NIH Toolbox is a multi-dimensional assessment tool that is used to measure the neurological and behavioral function of a patient over time. Assessments are recorded as 7 individual test scores, 1 total summary score and 2 composite scores. The raw measure scores and age-corrected standard scores and the change from baseline of the scores will be summarized using descriptive statistics at each visit.
EuroQol EQ-5D™ questionnaire to measure health and quality-of-life
Time frame: 6.5 years
EQ-5D™ is a standardized questionnaire as judged by the patients. This questionnaire consists of two parts: 1. Five domains: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension consists of 5 levels of grading: no problem, slight problem, moderate problem, severe problem and extreme problem. For youths, 3 levels of grading: no problem, some problems, and a lot of problems. 2. Visual analogue scale (VAS) is a vertical scale from 0 (worst) to 100 (best). Descriptive statistics will be provided for the five domains. Descriptive statistics will be provided for VAS and change from baseline at each visit for pooled EQ-5D-Y version and EQ-5D-5L version.
Dual-Energy X-Ray Absorptiometry to measure bone mineral density
Time frame: 6.5 years
The z-score, t-score, and bone mineral density and change from baseline will be summarized by the location of X-ray (spine, hip, and total body) at each visit.
Eye assessments to evaluate ocular health: Visual acuity examination will be performed to determine the clarity or sharpness of vision
Time frame: 6.5 years
Visual acuity examination will be performed to determine the clarity or sharpness of vision. The results will be summarized using descriptive statistics at each visit.
Eye assessments to evaluate ocular health: Slit lamp eye examination will be performed to look for any diseases or abnormalities in the anterior portion of the eye
Time frame: 6.5 years
Slit lamp eye examination will be performed to look for any diseases or abnormalities in the anterior portion of the eye. The results will be summarized using descriptive statistics at each visit.
7 secondary outcomes
Growth and development: World Health Organization (WHO) growth charts will be used to document height in centimeters (cm) for age 1 to 19 years old. Routine methods will be used to document height for all other age groups.
Time frame: 6.5 years
Growth and development: World Health Organization (WHO) growth charts will be used to document Body Mass Index (BMI) in kilograms per meter square for age 1 to 19 years old. Routine methods will be used to document BMI for all other age groups.
Time frame: 6.5 years
Growth and development: World Health Organization (WHO) growth charts will be used to document weight in kilograms (kg) for age 1 to 19 years old. Routine methods will be used to document weight for all other age groups.
Time frame: 6.5 years
Changes in alanine aminotransferase (ALT)
Time frame: 6.5 years
Changes in aspartate aminotransferase (AST)
Time frame: 6.5 years
Changes in alkaline phosphatase (ALP)
Time frame: 6.5 years
Optional homocystinuria genetic testing
Time frame: The optional test will be done once at screening visit
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Sep 2026.
- Individual participant dataSharing planned: 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.
Related trials for Homocystinuria Due to CBS Deficiency
RecruitingPhase 3
Pegtibatinase as a Treatment for Participants With Classical Homocystinuria (HCU) Receiving Standard of Care Treatment
Homocystinuria
Enrolling by invitationPhase 3
A Long-term Extension Study to Assess the Long-term Safety and Efficacy of Pegtibatinase Treatment in Participants ≥5 to ≤65 Years of Age With Classical Homocystinuria (HCU) (ENSEMBLE)
Homocystinuria
RecruitingObservational study
Health Related Quality of Life (HrQoL) in Classical Homocystinuria (CBS Deficiency)
Homocystinuria
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Michael Imperiale, MD study director
Travere Therapeutics, Inc.
11 sites in 4 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Homocystinuria Due to CBS Deficiency, run by Travere Therapeutics, Inc. at 11 sites in 4 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 9 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 11 sites in United States, Qatar, Ireland, United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in Met cycle metabolites levels - tHcy (time frame: 6.5 years). The study lists 11 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Sep 2026.