Evaluating N-Acetyl-L-Leucine for Ataxia-Telangiectasia

Effects of N-Acetyl-L-Leucine on Ataxia-Telangiectasia (A-T: A Phase III, Randomized, Placebo-controlled, Double-blind, Crossover Study

PHASE3 · IntraBio Inc · NCT06673056

This study is testing whether a new medication called N-Acetyl-L-Leucine can help improve symptoms for people aged 4 and older with Ataxia-Telangiectasia.

Quick facts

PhasePHASE3
Study typeInterventional
Enrollment60 (estimated)
Ages4 Years and up
SexAll
SponsorIntraBio Inc (industry)
Locations11 sites (Los Angeles, California and 10 other locations)
Trial IDNCT06673056 on ClinicalTrials.gov

What this trial studies

This pivotal, randomized, double-blind, placebo-controlled, multi-center therapeutic study aims to assess the safety, tolerability, and efficacy of N-Acetyl-L-Leucine (IB1001) in patients aged 4 and older with a confirmed diagnosis of Ataxia-Telangiectasia (A-T). Participants will undergo a baseline assessment followed by two 12-week treatment periods, where they will receive either IB1001 or a placebo in a crossover design. The study will evaluate the effects of the treatment on the symptoms of A-T and may offer an extension phase for continued access to the medication for participants. The goal is to determine if IB1001 provides significant benefits over standard care.

Who should consider this trial

Good fit: Ideal candidates are males and females aged 4 years and older with a genetically confirmed diagnosis of Ataxia-Telangiectasia.

Not a fit: Patients without a confirmed diagnosis of Ataxia-Telangiectasia or those who do not meet the inclusion criteria will not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could improve the quality of life and functional abilities for patients with Ataxia-Telangiectasia.

How similar studies have performed: While this approach is novel for Ataxia-Telangiectasia, similar studies with N-Acetyl-L-Leucine have shown promise in other conditions, suggesting potential for success.

Eligibility criteria

Show full inclusion / exclusion criteria
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 genetically confirmed diagnosis of A-T 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:

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  1. hysteroscopic sterilization;
  2. 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 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:

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  1. A SARA score of 7 ≤ X ≤ 34 points (out of 40) AND
  2. 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 A-T, including those on the prohibited medication list. Non-prohibited medications/therapies, 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 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 flavor).
  3. Excipients the placebo sachet (namely isomalt, hypromellose, strawberry flavor, 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 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 washout period from any of the following prohibited medication prior to Visit 1 (Baseline 1) and remain without prohibited medication through Visit 6.

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  1. N-Acetyl-DL-Leucine (e.g. Tanganil®);
  2. N-Acetyl-L-Leucine (prohibited if not provided as IMP in the IB1001-303 trial);
  3. Sulfasalazine;
  4. Rosuvastatin.

Where this trial is running

Los Angeles, California and 10 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Ataxia-Telangiectasia, Louis Bar Syndrome

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.