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Taking peoplePhase 3

Tests N-acetyl-L-leucine in people with Niemann-Pick disease type C

Tests N-acetyl-L-leucine against placebo in people aged 4 and older with Niemann-Pick type C.

Plain-language title generated from the registry record
Registry title: A Pivotal Study of N-Acetyl-L-Leucine on Niemann-Pick Disease Type C

Key facts

Where
Parkville, AustraliaSee the site
Phase
Phase 3

AI summary: who the study is looking for

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for people aged 4 and older with a genetically confirmed Niemann-Pick disease type C (NPC) who can still walk or use their hands to a set degree.

Age
4 years and older
Sex
Men and women
Disease stage
Genetically confirmed NPC. SARA score from 7 to 34 points (out of 40). Also either a Gait subtest score within the 2-7 range (0-8 range) or a 9-Hole Peg Test with the dominant hand done in 20 to 150 seconds.
Earlier treatment
Allowed NPC medicines (such as miglustat), speech therapy and physiotherapy must be at a stable dose and type for at least 42 days before the first visit. Prohibited medicines must be stopped 42 days before the first visit: N-Acetyl-DL-Leucine (e.g. Tanganil), N-Acetyl-L-Leucine, sulfasalazine and rosuvastatin.
Biomarker or test result
A confirmed genetic diagnosis of NPC.

Main reasons for not taking part

  • Known allergy to acetyl-leucine or to the ingredients of the study or placebo sachets
  • In another clinical study, or took a study drug within 42 days before the first visit
  • Current or planned pregnancy, or breastfeeding
  • Weight under 15 kg (33 lb)
  • Severe vision or hearing problems, or joint, muscle or nerve disorders that affect study tests

Read by machine on 9 November 2026.

Where in Australia

  • The Royal Melbourne HospitalParkville, AustraliaNo longer taking part

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?
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Trial details

Who runs it
IntraBio Inc
Trial code
NCT05163288
Record updated
3 April 2026
Original description
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.Read full original descriptionShow less

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

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.

Inclusion: 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 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: 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; Known or persistent use, misuse, or dependency of medication, drugs, or alcohol; 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; -; 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); 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; 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; Current or planned pregnancy or women who are breastfeeding.

ClinicalTrials.gov NCT05163288