Who may be eligible for the A Pivotal Study of N-Acetyl-L-Leucine on Niemann-Pick Disease Type C trial?

Inclusion Criteria: 1. Written informed consent signed by the patient and/or their legal representative/ parent/ impartial witness 2. Male or female aged ≥4 years with a confirmed genetic diagnosis of NPC at the time of signing informed consent. 3. Females of childbearing potential, defined as a premenopausal female capable of becoming pregnant, will be included if they are either sexually inactive (sexually abstinent for 14 days prior to the first dose and confirm to continue through 28 days after the last dose) or using one of the following highly effective contraceptives (i.e. results in \<1% failure rate when used consistently and correctly) 14 days prior to the first dose continuing through 28 days after the last dose: 1. intrauterine device (IUD); 2. surgical sterilization of the partner (vasectomy for 6 months minimum); 3. combined (estrogen or progestogen containing) hormonal contraception associated with the inhibition of ovulation (either oral, intravaginal, or transdermal); 4. progestogen only hormonal contraception associated with the inhibition of ovulation (either oral, injectable, or implantable); 5. intrauterine hormone releasing system (IUS); 6. bilateral tubal occlusion. 4. Females of non-childbearing potential who have undergone one of the following sterilization procedures at least 6 months prior to the first dose: 1. hysteroscopic sterilization; 2. bilateral tubal ligation or bilateral salpingectomy; 3. hysterectomy; 4. bilateral oophorectomy; OR be postmenopausal with amenorrhea for at least 1 year prior to the first dose and follicle stimulating hormone (FSH) serum levels consistent with postmenopausal status. FSH analysis for postmenopausal women will be done at screening. FSH levels should be in the postmenopausal range as determined by the central laboratory. 5. Non-vasectomized male patient agrees to use a condom with spermicide or abstain from sexual intercourse during the study until 90 days beyond the last dose of study medication and the female partner agrees to comply with inclusion criteria 3 or 4. For a vasectomized male who has had his vasectomy 6 months or more prior to study start, it is required that they use a condom during sexual intercourse. A male who has been vasectomized less than 6 months prior to study start must follow the same restrictions as a non-vasectomized male. 6. If male, patient agrees not to donate sperm from the first dose until 90 days after their last dose. 7. Patients must fall within: a) A SARA score of 7 ≤ X ≤ 34 points (out of 40) AND b) Either: i. Within the 2-7 range (0-8 range) of the Gait subtest of the SARA scale OR ii. Be able to perform the 9-Hole Peg Test with Dominant Hand (9HPT-D) (SCAFI subtest) in 20 ≤ X ≤150 seconds. 8. Weight ≥15 kg at screening. 9. Patients are willing to disclose their existing medications/therapies for (the symptoms) of NPC including those on the prohibited medication list. Non-prohibited medications/therapies (authorized medicines for NPC \[e.g. miglustat\], speech therapy, and physiotherapy) are permitted provided: 1. The Investigator does not believe the medication/therapy will interfere with the study protocol/results 2. Patients have been on a stable dose/duration and type of therapy for at least 42 days before Visit 1 (Baseline 1) 3. Patients are willing to maintain a stable dose/do not change their therapy throughout the duration of the study. 10. An understanding of the implications of study participation, provided in the written patient information and informed consent by patients or their legal representative/parent, and demonstrates a willingness to comply with instructions and attend required study visits (for children this criterion will also be assessed in parents or appointed guardians). Exclusion Criteria: 1. Patients who are unable to consistently Patients who have any known hypersensitivity or history of hypersensitivity to: 1. Acetyl-Leucine (DL-, L-, D-) or derivatives. 2. Excipients the IB1001 sachet (namely isomalt, hypromellose, and strawberry flavour). 3. Excipients the placebo sachet (namely isomalt, hypromellose, strawberry flavour, citric acid, microcrystalline cellulose, lactose, denatonium benzoate). 2. Simultaneous participation in another clinical study or participation in any clinical study involving administration of an investigational medicinal product (IMP; 'study drug') for at least 42 days prior to Visit 1. At the discretion of the investigator, Medical Monitor, and Sponsor, the washout period for specific IMPs may be longer based on the pharmacological activity and pharmacokinetics of the drug. 3. Patients with a physical, cognitive, or psychiatric condition which, at the investigator's discretion and in consultation with the Medical Monitor and Sponsor (as applicable), may put the patient at risk, may confound the study results, or may interfere with the patient's participation in the clinical study, i.e. reliably perform study assessments. 4. Known or persistent use, misuse, or dependency of medication, drugs, or alcohol. 5. Current or planned pregnancy or women who are breastfeeding. 6. Patients with severe vision or hearing impairment (that is not corrected by glasses or hearing aids) that, at the investigator's discretion, interferes with their ability to perform study assessments. 7. Patients who have been diagnosed with arthritis or other musculoskeletal disorders affecting joints, muscles, ligaments, and/or nerves that by themselves affects patient's mobility and, at the investigator's discretion, interferes with their ability to perform study assessments. 8. Patients unwilling and/or not able to undergo a 42 day period from any of the following prohibited medication prior to Visit 1 (Baseline 1) and remain without prohibited medication through Visit 6. 1. N-Acetyl-DL-Leucine (e.g. Tanganil®); 2. N-Acetyl-L-Leucine (prohibited if not provided as IMP in the IB1001-301 trial); 3. Sulfasalazine; 4. Rosuvastatin. \-

ClinicalTrials.gov record NCT05163288

A Pivotal Study of N-Acetyl-L-Leucine on Niemann-Pick Disease Type C

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Jul 27, 2026

Effects of N-Acetyl-L-Leucine on Niemann-Pick Disease Type C (NPC): A Phase III, Randomized, Placebo-controlled, Double-blind, Crossover Study

About this page. This page shows the study's official ClinicalTrials.gov record ↗, with added help to make it easier to understand. We explain medical terms, highlight key details in plain language, and suggest questions you may want to ask the study team.

The record is periodically copied from ClinicalTrials.gov and may lag behind changes. AI summaries are checked by software, not a clinician.Read moreShow less

The official record is written by the study sponsor and published on ClinicalTrials.gov. It may not always reflect the latest changes. Before making any decisions, please confirm important information with the study team and your own healthcare team.

Where you see "AI summary", AI was used to create a plain-language explanation and software checked it against the source. It has not been reviewed by a clinician, so it may contain mistakes or leave out important details.

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.

Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.

PhasePhase 3A later-stage study, usually with more participants, designed to give stronger evidence about how well a treatment works and how safe it is. It often compares the treatment with standard care or a placebo, and results may support an application for approval.

Age4 years old and older

SexAll

LocationAustralia, Czechia, Germany, Netherlands, Slovakia, Switzerland, United Kingdom, United States

AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This is a Phase III randomized, quadruple-blind, placebo-controlled crossover study of N-Acetyl-L-Leucine (IB1001) in people aged 4 years and older with a confirmed genetic diagnosis of Niemann-Pick disease type C (NPC). After a ~2-week baseline, participants are randomized 1:1 to receive IB1001 or placebo for a ~12-week Period I, then switch to the opposite treatment for a ~12-week Period II; assessments occur twice in each period. A planned open-label Extension Phase is available and may provide up to 3 years of IB1001 for eligible participants.

What it is studying. The study evaluates the safety, tolerability, and efficacy of N-Acetyl-L-Leucine (IB1001) compared with placebo in people with NPC, using measures of ataxia and other clinical and quality-of-life assessments.

What the researchers hope to learn. To determine whether IB1001 is safe and well tolerated in people with NPC and to assess its effects on ataxia (measured by the Scale for the Assessment and Rating of Ataxia or a modified SARA in the US), on functional performance (SCAFI), disability rating, clinician/caregiver/patient global impressions, and quality of life (EQ-5D).

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

A pivotal, randomized, double-blind, placebo controlled, multi-center therapeutic study for patients age 4 and older with a confirmed diagnosis of Niemann Pick disease type C (NPC). The objective of this study is to evaluate the safety, tolerability and efficacy of N-acetyl-L-leucine (IB1001) compared to standard of care. Following this randomized, double-blind, placebo-controlled "Parent Study", an extension phase is conducted for (1) patients who completed the "Parent Study" and (2) patients who are enrolled directly into the Extension Phase. Currently, the Extension Phase provides patients with 3 years of open-label treatment.

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Drug: N-Acetyl-L-Leucine
Other: Placebo

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

Written informed consent signed by the patient and/or their legal representative/ parent/ impartial witness
Male or female aged ≥4 years with a confirmed genetic diagnosis of NPC at the time of signing informed consent.
Females of childbearing potential, defined as a premenopausal female capable of becoming pregnant, will be included if they are either sexually inactive (sexually abstinent for 14 days prior to the first dose and confirm to continue through 28 days after the last dose) or using one of the following highly effective contraceptives (i.e. results in <1% failure rate when used consistently and correctly) 14 days prior to the first dose continuing through 28 days after the last dose:
intrauterine device (IUD);
surgical sterilization of the partner (vasectomy for 6 months minimum);
combined (estrogen or progestogen containing) hormonal contraception associated with the inhibition of ovulation (either oral, intravaginal, or transdermal);
progestogen only hormonal contraception associated with the inhibition of ovulation (either oral, injectable, or implantable);
intrauterine hormone releasing system (IUS);
bilateral tubal occlusion.
Females of non-childbearing potential who have undergone one of the following sterilization procedures at least 6 months prior to the first dose:
hysteroscopic sterilization;
bilateral tubal ligation or bilateral salpingectomy;
hysterectomy;
bilateral oophorectomy; OR be postmenopausal with amenorrhea for at least 1 year prior to the first dose and follicle stimulating hormone (FSH) serum levels consistent with postmenopausal status. FSH analysis for postmenopausal women will be done at screening. FSH levels should be in the postmenopausal range as determined by the central laboratory.
Non-vasectomized male patient agrees to use a condom with spermicide or abstain from sexual intercourse during the study until 90 days beyond the last dose of study medication and the female partner agrees to comply with inclusion criteria 3 or 4.
For a vasectomized male who has had his vasectomy 6 months or more prior to study start, it is required that they use a condom during sexual intercourse. A male who has been vasectomized less than 6 months prior to study start must follow the same restrictions as a non-vasectomized male.
If male, patient agrees not to donate sperm from the first dose until 90 days after their last dose.
Patients must fall within:
a) A SARA score of 7 ≤ X ≤ 34 points (out of 40) AND b) Either: i. Within the 2-7 range (0-8 range) of the Gait subtest of the SARA scale OR ii. Be able to perform the 9-Hole Peg Test with Dominant Hand (9HPT-D) (SCAFI subtest) in 20 ≤ X ≤150 seconds.
Weight ≥15 kg at screening.
Patients are willing to disclose their existing medications/therapies for (the symptoms) of NPC including those on the prohibited medication list. Non-prohibited medications/therapies (authorized medicines for NPC [e.g. miglustat], speech therapy, and physiotherapy) are permitted provided:
The Investigator does not believe the medication/therapy will interfere with the study protocol/results
Patients have been on a stable dose/duration and type of therapy for at least 42 days before Visit 1 (Baseline 1)
Patients are willing to maintain a stable dose/do not change their therapy throughout the duration of the study.
An understanding of the implications of study participation, provided in the written patient information and informed consent by patients or their legal representative/parent, and demonstrates a willingness to comply with instructions and attend required study visits (for children this criterion will also be assessed in parents or appointed guardians).

Exclusion criteria

Patients who are unable to consistently Patients who have any known hypersensitivity or history of hypersensitivity to:
Acetyl-Leucine (DL-, L-, D-) or derivatives.
Excipients the IB1001 sachet (namely isomalt, hypromellose, and strawberry flavour).
Excipients the placebo sachet (namely isomalt, hypromellose, strawberry flavour, citric acid, microcrystalline cellulose, lactose, denatonium benzoate).
Simultaneous participation in another clinical study or participation in any clinical study involving administration of an investigational medicinal product (IMP; 'study drug') for at least 42 days prior to Visit 1. At the discretion of the investigator, Medical Monitor, and Sponsor, the washout period for specific IMPs may be longer based on the pharmacological activity and pharmacokinetics of the drug.
Patients with a physical, cognitive, or psychiatric condition which, at the investigator's discretion and in consultation with the Medical Monitor and Sponsor (as applicable), may put the patient at risk, may confound the study results, or may interfere with the patient's participation in the clinical study, i.e. reliably perform study assessments.
Known or persistent use, misuse, or dependency of medication, drugs, or alcohol.
Current or planned pregnancy or women who are breastfeeding.
Patients with severe vision or hearing impairment (that is not corrected by glasses or hearing aids) that, at the investigator's discretion, interferes with their ability to perform study assessments.
Patients who have been diagnosed with arthritis or other musculoskeletal disorders affecting joints, muscles, ligaments, and/or nerves that by themselves affects patient's mobility and, at the investigator's discretion, interferes with their ability to perform study assessments.
Patients unwilling and/or not able to undergo a 42 day period from any of the following prohibited medication prior to Visit 1 (Baseline 1) and remain without prohibited medication through Visit 6.
N-Acetyl-DL-Leucine (e.g. Tanganil®);
N-Acetyl-L-Leucine (prohibited if not provided as IMP in the IB1001-301 trial);
Sulfasalazine;
Rosuvastatin.
-

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Detailed description from the registry

This is a multinational, randomized, placebo-controlled, double-blinded, cross-over Phase III study that will assess the safety and efficacy of N-Acetyl-L-Leucine (IB1001) versus Placebo for the treatment of Niemann-Pick type C disease (NPC). Patients will be assessed during three study periods: a baseline period (approximately 2-weeks), after which they will be randomized (1:1) to receive treatment with IB1001 or Placebo for approximately 12-weeks during the first intervention period ("Period I"). Following Period I, patients will crossover to receive the opposite treatment (IB1001 or Placebo) for approximately 12-weeks during a second intervention period ("Period II). Patients will be assessed twice during each study period. Patients who have participated in the study may be offered the opportunity to roll over into an Extension Phase, which is planned to allow patients to have further access to IB1001.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

After about a 2‑week baseline period, participants are randomized 1:1 to receive either IB1001 (N‑Acetyl‑L‑Leucine) or matching placebo for about 12 weeks (Period I), then cross over to the opposite treatment for about 12 weeks (Period II). Study visits include clinical assessments performed twice in each period; the study uses ataxia and function scales and other clinical ratings. The study drug is taken orally as granules in a sachet (patients ≥13 years receive 4 g/day divided into three doses; children <13 receive weight‑tiered doses). Eligible participants must follow contraception and sperm/donation rules, keep allowed background therapies stable, avoid prohibited medications for specified washout periods, and may be offered enrollment in an open‑label Extension Phase that provides 3 years of treatment.

How the study is structured. Participants enter a short baseline (~2 weeks), then are randomized 1:1 to IB1001 or placebo. The trial uses a crossover design: each participant receives one treatment for about 12 weeks (Period I) then switches to the other for about 12 weeks (Period II). The study is quadruple-blind (participant, care provider, investigator, and outcomes assessor blinded). Those who complete—or who enroll directly into—the Extension Phase may receive open-label IB1001 for up to about 3 years.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

Some participants receive a placebo. How is that decided, and what happens for placebo-group participants when the study ends?
The listed sites are in Australia, Czechia, Germany, Netherlands, Slovakia, Switzerland, United Kingdom, United States. Is any of them reachable for me, and does the study help with travel?
Which of the eligibility criteria would need to be checked with tests before I could join?

More on Niemann-Pick disease type C

Clinical trials15 trials listed for Niemann-Pick disease type CEvery trial the registry lists for Niemann-Pick disease type C, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in Niemann-Pick disease type C researchLatest monthly update: September 2026. Includes: Gene change range. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start: Jun 30, 2022
Primary completion: Jun 12, 2030 (estimated)
Study completion: December 2030 (estimated)
Target enrollment: 53 participants (estimated)
Last updated on registry: Apr 3, 2026
Data verified: Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor: IntraBio Inc

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Michael Strupp, MD 📞 +44 8081 641283 ✉ mstrupp@intrabio.com
Taylor Fields 📞 +44 8081 641283 ✉ tfields@intrabio.com

Participating sites (14)

Filter by country:

Mayo ClinicCompleted
Rochester, Minnesota, 55905 · United States
The Royal Melbourne HospitalActive Not Recruiting
Parkville, Victoria, 3050 · Australia
First Faculty of Medicine, Charles University Hospital PragueActive Not Recruiting
Prague, 128 08 · Czechia
University of GiessenActive Not Recruiting
Giessen, 35389 · Germany
University of HamburgCompleted
Hamburg, 20246 · Germany
SphinCS - Institute of Clinical Science in Lysosomal Storage DisordersActive Not Recruiting
Höchheim, 65239 · Germany
Ludwig Maximilian University of MunichNot Yet Recruiting
München, 80539 · Germany
- Susanne Schneider-Pils, MD · +49 (0)89 4400 7677 · susanne.schneider@med.uni-muenchen.de
- Susanne Schneider-Pils, MD
University Hospital MünsterActive Not Recruiting
Münster, 48149 · Germany
Amsterdam UMCRecruiting
Amsterdam, 1105 · Netherlands
- Marion Brands, MD · m.m.brands@amsterdamumc.nl
- Marion Brands, MD
Comenius University in BratislvaActive Not Recruiting
Bratislava, 833 40 · Slovakia

Terms used on this page · explanations by MedicalUpdates.ai

randomized: Participants are assigned to the study groups by chance, like a coin toss, rather than chosen by the doctor or the participant. This is done so the groups are comparable.
double-blind: Two types of people involved in the study do not know which intervention a participant is receiving. The ClinicalTrials.gov record specifies who is masked, for example participants, care providers, investigators or outcome assessors.
placebo controlled: A study design in which one group receives a placebo so that the study treatment's effects can be compared with no active treatment.
standard of care: Treatment generally considered appropriate for a condition in a particular clinical setting. It can vary by patient, place and over time. In many studies the new treatment is added to, or compared with, standard of care.
open-label: No masking is used, so the assigned intervention is not deliberately hidden from participants or study staff.
Written informed consent: The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
legal representative: A person who is legally allowed to make decisions, including consent to research, on behalf of someone who cannot consent for themselves.
childbearing potential: Studies often ask participants who could become pregnant, or could father a child, to use contraception during the study and for a period afterwards, because the effect of the treatment on a pregnancy is unknown.
at screening: The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
inclusion criteria: The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
prohibited medication: A medicine that participants may not use during the study, usually because it could interfere with the study treatment or its measurement.
stable dose: A dose that has not changed for a defined period before the study starts. Studies may require this so that background treatment is relatively stable when study measurements begin.
Baseline: Measurements taken at the start of the study, before any study treatment, so that later results can be compared with them.
placebo: A treatment that looks like the study treatment but contains no active ingredient. Some participants receive it instead of the study treatment, usually without knowing which they got.
investigational: A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
Sponsor: The organisation or person that initiates the study and has authority over it. The sponsor may be a company, hospital, university, government agency or individual, and is not necessarily the organisation that funds the study.
washout period: A period during which a participant stops a previous treatment before starting the study treatment, so the earlier treatment does not affect the results.
pharmacokinetics: How the body absorbs, distributes, breaks down and removes a drug. It is studied by measuring drug levels or related substances at set times after a dose.
Exclusion Criteria: The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
blinded: Who does not know which intervention a participant is receiving. It can apply to participants, the people giving the treatment, those assessing results, or those analysing the data.
cross-over: Each participant receives more than one intervention, one after the other, usually with a gap (a washout) in between. Participants act as their own comparison.
1:1: How many participants go to each group. In a 2:1 ratio, two are assigned to the first group for every one assigned to the second.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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