TerminatedNCT03759678Updated Mar 25, 2026Results posted

N-Acetyl-L-Leucine for Ataxia-Telangiectasia (A-T)

A Phase 2 interventional study of IB1001 in Ataxia Telangiectasia, sponsored by IntraBio Inc. Terminated at 4 sites in 4 countries. Open to participants aged 6 Years and older. Per ClinicalTrials.gov, last updated 2026-03-25.

Sponsored by IntraBio Inc · Phase 2, Interventional, and Treatment

Why this study was terminated

Determined priority was to recruit directly to the pivotal Phase III double-blind, placebo-controlled, randomised study (NCT07221292).

Phase: Phase 2
Study type: Interventional
Enrollment: 17
Allocation: Non-randomized
Ages: 6 Years and older
Sex: All

Study summary

This is a multinational, multicenter, open-label, rater-blinded prospective Phase II study which will assess the safety and efficacy of N-Acetyl-L-Leucine (IB1001) for the treatment of Ataxia-Telangiectasia (A-T).

There are two phases to this study: the Parent Study, and the Extension Phase.

The Parent Study evaluates the safety and efficacy of N-Acetyl-L-Leucine (IB1001) for the symptomatic treatment of A-T.

The Extension Phase evaluates the long-term safety and efficacy of IB1001 for the neuroprotective, disease-modifying treatment of A-T.

Read the detailed description

The primary purpose of the study is to evaluate the safety and efficacy of N-Acetyl-L-Leucine (IB1001) in the treatment of A-T investigating the efficacy in terms of improving symptoms, functioning, and quality of life against the defined endpoints in patients with A-T.

Patients will be assessed during three study phases: a baseline period, a 6-week treatment period, and a 6-week post-treatment washout period. If within 6 weeks prior to the initial screening visit, a patient has received any of the prohibited medications defined in the eligibility criteria (irrespective of the preceding treatment duration) a wash-out study-run in of 6 weeks is required prior to the first baseline assessment.

All patients will receive the study drug during this study.

For each individual patient, the study lasts for approximately 3.5 - 4 months during which there are 6 study visits to the study site.

This Extension Phase allows patients who have completed the Parent Study to, at the discretion of the Principal Investigator (PI), continue treatment with N-Acetyl-L-Leucine (IB1001). Patients will receive treatment with IB1001 for two one-year treatment periods, separated by a 6-week washout. All patients will receive the study drug during the treatment period. For each individual patient, the Extension Phase lasts for approximately 25.5 months, during which there are 6 visits to the study site.

Conditions studied

Ataxia Telangiectasia

Browse trials for

Ataxia Telangiectasia 40

Who can participate

Ages eligible: 6 Years and older
Sexes eligible: All
Accepts healthy volunteers: No

Inclusion criteria

Individuals who meet all of the following criteria are eligible to participate in the study:

Written informed consent signed by the patient and/or their legal representative/ parent
Male or female aged ≥6 years with a confirmed diagnosis of A-T 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 continuing 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.
Females of non-childbearing potential must 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.
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, the patient agrees not to donate sperm from the first dose until 90 days after dosing.
Patients must fall within:
a) A Scale for the assessment and rating of ataxia (SARA) score of 5 ≤ X ≤ 33 points (out of 40) AND i. Within the 2-7 range (out of 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 A-T, including those on the prohibited medication list. Non-prohibited medications/therapies (e.g. concomitant 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 6 weeks 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.
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

Exclusion Criteria

Individuals who meet any of the following criteria are not eligible to participate in the study:

Asymptomatic patients
Patient has clinical features of A-T, but a completely negative result on a previous genetic test for A-T.
Patients who have any of the following:
1. Chronic diarrhea;
2. Unexplained visual loss;
3. Malignancies;
4. Insulin-dependent diabetes mellitus.
5. Known history of hypersensitivity to the N-Acetyl-Leucine (DL-, L-, D-) or derivatives.
6. History of known hypersensitivity to excipients of Ora-Blend® (namely sucrose, sorbitol, cellulose, carboxymethylcellulose, xanthan gum, carrageenan, dimethicone, methylparaben, and potassium sorbate).
Simultaneous participation in another clinical study or participation in any clinical study involving administration of an investigational medicinal product (IMP; 'study drug') within 6 weeks prior to Visit 1.
Patients with a physical or psychiatric condition which, at the investigator's discretion, may put the patient at risk, may confound the study results, or may interfere with the patient's participation in the clinical study.
Known clinically-significant (at the discretion of the investigator) laboratories in hematology, coagulation, clinical chemistry, or urinalysis, including, but not limited to:
1. Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) >5x upper limit of normal (ULN);
2. Total bilirubin >1.5x ULN, unless Gilbert's syndrome is present in which case total bilirubin >2x ULN.
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 6-week washout period from any of the following prohibited medication prior to Visit 1 (Baseline 1) and remain without prohibited medication through Visit 6.
1. Aminopyridines (including sustained-release form);
2. N-Acetyl-DL-Leucine (e.g. Tanganil®);
3. N-Acetyl-L-Leucine (prohibited if not provided as IMP);
4. Riluzole;
5. Gabapentin;
6. Varenicline;
7. Chlorzoxazone;
8. Sulfasalazine;
9. Rosuvastatin.

Study design

Phase: Phase 2
Primary purpose: Treatment
Allocation: Non-randomized
Intervention model: Single group
Masking: Single (Outcomes assessor)
Enrollment: 17 participants (actual)

Study arms

Experimental
Treatment with IB1001
6-weeks treatment with IB1001 administered orally. Patients ≥13 years old will receive a total daily dose of 4 g/day (administered as 3 doses per day). Patients 6-12 years old will receive weight-tiered doses: * Patients aged 6-12 years weighing 15 to \<25 kg will take 2 g per day: 1 g in the morning and 1 g in the evening. * Patients aged 6-12 years weighing 25 to \<35 kg will take 3 g per day: 1 g in the morning, 1 g in the afternoon, and 1 g in the evening. * Patients aged 6-12 years weighing ≥35 kg will take 4 g per day: 2 g in the morning, 1g in the afternoon and 1 g in the evening (as per adults) After the 6-week treatment period, patients will enter a 6-week post-treatment washout period.
Drug: IB1001
No intervention
Post-Treatment Washout
After the 6-week treatment period, patients will enter a 6-week post-treatment washout period.

Interventions

DrugIB1001
IB1001 (N-Acetyl-L-Leucine) is a modified amino-acid ester that is orally administered.
Also known as: N-Acetyl-L-Leucine

What researchers measure

Primary outcomes

Clinical Impression of Change in Severity (CI-CS) [Fields et al. 2021]
The Clinical Impression of Change in Severity assessment will instruct the blinded rater to consider: compared to the first video, how has the severity of their performance on the 9 Hole Peg Test of the Dominant Hand (9HPT-D) or 8 Meter Walk Test (8MWT) changed (improved or worsened) in 6-weeks as observed in the second video? The Clinical Impression of Change in Severity is evaluated on a 7 point Likert scale (+3=significantly improved to -3= significantly worse). Change values were calculated for each period, i.e. treatment with IB1001 (comparing the end of treatment (Visit 4) with baseline (Visit 2)) and post-treatment washout (comparing the end of washout (Visit 6) with the end of treatment (Visit 4)). Then, the mean change obtained in the post-treatment period was subtracted from the mean change obtained for the treatment with IB1001 period, with a positive value indicating an improvement in the treatment period compared to the post-treatment washout period.
Time frame: CI-CS comparing Baseline (Day 1) with IB1001 versus the end of 6-weeks treatment with IB1001 (Approximately Day 42) MINUS the CI-CS comparing the end of 6-weeks treatment with IB1001 (Approximately Day 42) versus the end of 6-weeks post-treatment washout

Secondary outcomes

Key Secondary Endpoint: Change in Severity Based on Average CI-S
The Change in Severity assessment will instruct the blinded rater to consider the severity of the patient at each visit. The Clinical Impression of Severity (CI-S)-assessment ranged from +3 ="normal not ill at all" to -3="among the most extremely ill patients ". Change values were calculated for each period, i.e. treatment with IB1001 (change between the baseline period \[average for Visit 1 and Visit 2\] and end of treatment period \[average for Visit 3 and Visit 4\]) and post-treatment washout (between end of treatment period \[average for Visit 3 and Visit 4\] and end of washout period \[average for Visit 5 and Visit 6\]). Then, the mean change in the post-treatment period was subtracted from the mean change in the treatment with IB1001 period.
Time frame: (CI-S comparing baseline period [average for Visit 1 and 2] and end of treatment period [average for Visit 3 and 4]) MINUS (change in CI-S between end of treatment period [average for Visit 3 and 4] and end of washout period [average for Visit 5 and 6])
Secondary Efficacy Endpoint: Individual Components of CI-CS
The Clinical Impression of Change in Severity assessment will instruct the blinded rater to consider: compared to the first video, how has the severity of their performance on the 9 Hole Peg Test of the Dominant Hand (9HPT-D) or 8 Meter Walk Test (8MWT) changed (improved or worsened) in 6-weeks as observed in the second video? The Clinical Impression of Change in Severity is evaluated on a 7 point Likert scale (+3=significantly improved to -3= significantly worse). Change values were calculated for each period, i.e. treatment with IB1001 (comparing the end of treatment (Visit 4) with baseline (Visit 2)) and post-treatment washout (comparing the end of washout (Visit 6) with the end of treatment (Visit 4)).
Time frame: Baseline to end of treatment with IB1001 (Parent Study 6-weeks treatment); End of treatment with IB1001 to the end of post 6-week treatment washout.
Secondary Efficacy Endpoint: CI-CS Score Reclassified on a 3-Point Scale
The Clinical Impression of Change in Severity assessment will instruct the blinded rater to consider: compared to the first video, how has the severity of their performance on the 9 Hole Peg Test of the Dominant Hand (9HPT-D) or 8 Meter Walk Test (8MWT) changed (improved or worsened) in 6-weeks as observed in the second video? The Clinical Impression of Change in Severity is evaluated on a 7 point Likert scale (+3=significantly improved to -3= significantly worse). CI-CS scores \<0 were reclassified as worsened (-1), CI-CS scores 0 remained classified as not changed (0), and CI-CS scores \>0 were reclassified as improved (+1). When comparing Visit 4 versus Visit 2 and Visit 6 versus Visit 4, CI-CS scores \<0 were reclassified as worsened (-1), CI-CS scores 0 remained classified as not changed (0), and CI-CS scores \>0 were reclassified as improved (+1).
Time frame: Baseline to end of treatment with IB1001 (Parent Study 6-weeks treatment); End of treatment with IB1001 to the end of post 6-week treatment washout
Secondary Efficacy Endpoint: CI-CS Score for the Non-Primary Anchor Test
The Clinical Impression of Change in Severity assessment will instruct the blinded rater to consider: compared to the first video, how has the severity of their performance on the 9 Hole Peg Test of the Dominant Hand (9HPT-D) or 8 Meter Walk Test (8MWT) changed (improved or worsened) in 6-weeks as observed in the second video? The Clinical Impression of Change in Severity is evaluated on a 7 point Likert scale (+3=significantly improved to -3= significantly worse). Change values were calculated for each period, i.e. treatment with IB1001 (comparing the end of treatment (Visit 4) with baseline (Visit 2)) and post-treatment washout (comparing the end of washout (Visit 6) with the end of treatment (Visit 4)).
Time frame: CI-CS of the non-primary anchor test was evaluated, comparing the CI-CS of Visit 4 (end of treatment) versus Visit 2 (baseline) and of Visit 6 (end of washout) versus Visit 4 (end of treatment) as done for the primary anchor test.
Secondary Efficacy Endpoint: Change in the Scale for Assessment and Rating of Ataxia (SARA) Score [Schmitz-Hübsch Etal, 2006; Subramony, 2007]
The Scale for Assessment and Rating of Ataxia has 8 items that are related to gait, stance, sitting, speech, finger-chase test, nose-finger test, fast alternating movements, and heel-shin test. The range is 0-40 points, with a lower score representing neurological improvement and a higher score representing neurological worsening. Change values were calculated for each period, i.e. treatment with IB1001 (comparing the end of treatment (Visit 4) with baseline (Visit 2)) and post-treatment washout (comparing the end of washout (Visit 6) with the end of treatment (Visit 4)).
Time frame: Baseline (Day 1) to end of treatment with IB1001 (Approximately Day 42); End of treatment with IB1001 (Approximately Day 42) to the end of post-treatment washout (Approximately Day 84)
Secondary Efficacy Endpoint: Spinocerebellar Ataxia Functional Index (SCAFI) [Schmitz-Hübsch et al, 2008]
Spinocerebellar Ataxia Functional Index (SCAFI) is composed of 8 Meter Walk Test, 9-Hole Peg Test of Dominant and Non-Dominant Hand (9HPT-D/9HPT-ND) (the 3 tests are timed assessments; each is done twice and values are averaged; the 8MWT and 9HPT-D and 9HPT-ND values are converted from times to rates, and the results expressed as a composite Z-score of each test relative to baseline) and the PATA rate (counted number how often a patient can repeat the syllables "PATA" within 10 seconds), a measure of speech performance. The scores of these 3 were transformed to Z-scores (=individual's average of both trials to perform the respective task -mean of study population at baseline) / SD of study population at baseline). A Z-score of 0 equates to the population mean at baseline. For all 3, higher Z-scores (above mean) mean better performance. The SCAFI total score was calculated as the arithmetic mean of the non-missing Z-scores for the 3. A higher total score means better performance.
Time frame: Baseline (Day 1) to end of treatment with IB1001 (Approximately Day 42); End of treatment with IB1001 (Approximately Day 42) to the end of post-treatment washout (Approximately Day 84)
Secondary Efficacy Endpoint: EuroQuol- 5 Dimension (EQ-5D) Quality of Life Scale
For posting, health-related quality of life based on the EQ-5D visual analogue scale (VAS) was presented as a secondary endpoint. EQ-5D VAS is a 0-100 scale where patients are asked to indicate their overall health, with a score of 0 indicating worst health and a score of 100 indicating best health.
Time frame: Baseline (Day 1) to end of treatment with IB1001 (Approximately Day 42); End of treatment with IB1001 (Approximately Day 42) to the end of post-treatment washout (Approximately Day 84)
Secondary Efficacy Endpoint: Clinical Global Impression of Severity (Treating Physician, Caregiver, Patient)
The Clinical Global Impression of Severity(CGI-S) evaluates the question "Considering your total (clinical) experience with this particular population, how ill is the patient (how ill are you) at this time?" based on answers from the treating physician, the caregiver, or the patients (if able). This was rated on the following seven-point scale: 1=normal, not at all ill; 2=borderline ill; 3=mildly ill; 4=moderately ill; 5=markedly ill; 6=severely ill; 7=among the most extremely ill the patient has been/I have ever been.
Time frame: Visits of Parent study: Visit 1 (Day -14), Visit 2 (Day 1), Visit 3 (Day 28), Visit 4 (Day 42), Visit 5 (Day 70), and Visit 6 (Day 84).
Secondary Efficacy Endpoint: Clinical Global Impression of Change (Treating Physician, Caregiver, Patient)
The Clinical Global Impression of Change assessed by the investigator is evaluated on a 7 point Likert scale ranging from 1='very much improved' to 7='very much worse' Change values were calculated for each period, i.e. treatment with IB1001 (comparing the end of treatment (Visit 4) with baseline (Visit 2)) and post-treatment washout (comparing the end of washout (Visit 6) with the end of treatment (Visit 4)).
Time frame: Baseline (Day 1) to end of treatment with IB1001 (Approximately Day 42); End of treatment with IB1001 (Approximately Day 42) to the end of post-treatment washout (Approximately Day 84)

Results

Posted Mar 25, 2026

Limitations and caveats

This study was ongoing during the COVID-19 pandemic, and the conduct of this study was impacted by the COVID-19 pandemic. Additionally, it was determined by the Sponsor that a Phase III, double-blind, randomized, placebo- controlled study for A-T should be conducted to support the marketing application with IB1001 for A-T (NCT NCT06673056). Accordingly, the IB1001-203 clinical study was terminated prior to reaching the target recruitment, to prioritize the pivotal Phase III trial.

Participant flow

Treatment with IB1001

Participant flow — Treatment with IB1001
Milestone	Parent Study
Started	17
Completed	16
Not completed	1
Withdrew: Adverse event	1

Post-Treatment Washout

Participant flow — Post-Treatment Washout
Milestone	Parent Study
Started	16
Completed	16
Not completed	0

Extension Phase

Participant flow — Extension Phase
Milestone	Parent Study
Started	13
Completed	10
Not completed	3
Withdrew: Adverse event	1
Withdrew: Withdrawal by subject	1
Withdrew: Lost to follow-up	1

Outcome measures

PrimaryClinical Impression of Change in Severity (CI-CS) [Fields et al. 2021]

The Clinical Impression of Change in Severity assessment will instruct the blinded rater to consider: compared to the first video, how has the severity of their performance on the 9 Hole Peg Test of the Dominant Hand (9HPT-D) or 8 Meter Walk Test (8MWT) changed (improved or worsened) in 6-weeks as observed in the second video? The Clinical Impression of Change in Severity is evaluated on a 7 point Likert scale (+3=significantly improved to -3= significantly worse). Change values were calculated for each period, i.e. treatment with IB1001 (comparing the end of treatment (Visit 4) with baseline (Visit 2)) and post-treatment washout (comparing the end of washout (Visit 6) with the end of treatment (Visit 4)). Then, the mean change obtained in the post-treatment period was subtracted from the mean change obtained for the treatment with IB1001 period, with a positive value indicating an improvement in the treatment period compared to the post-treatment washout period.

Time frame:: CI-CS comparing Baseline (Day 1) with IB1001 versus the end of 6-weeks treatment with IB1001 (Approximately Day 42) MINUS the CI-CS comparing the end of 6-weeks treatment with IB1001 (Approximately Day 42) versus the end of 6-weeks post-treatment washout
Reported as:: Mean · Score on a scale

Clinical Impression of Change in Severity (CI-CS) [Fields et al. 2021]
Score on a scale	Parent Study
Clinical Impression of Change in Severity (CI-CS) [Fields et al. 2021]	0.16 ± 1.65

SecondaryKey Secondary Endpoint: Change in Severity Based on Average CI-S

The Change in Severity assessment will instruct the blinded rater to consider the severity of the patient at each visit. The Clinical Impression of Severity (CI-S)-assessment ranged from +3 ="normal not ill at all" to -3="among the most extremely ill patients ". Change values were calculated for each period, i.e. treatment with IB1001 (change between the baseline period \[average for Visit 1 and Visit 2\] and end of treatment period \[average for Visit 3 and Visit 4\]) and post-treatment washout (between end of treatment period \[average for Visit 3 and Visit 4\] and end of washout period \[average for Visit 5 and Visit 6\]). Then, the mean change in the post-treatment period was subtracted from the mean change in the treatment with IB1001 period.

Time frame:: (CI-S comparing baseline period [average for Visit 1 and 2] and end of treatment period [average for Visit 3 and 4]) MINUS (change in CI-S between end of treatment period [average for Visit 3 and 4] and end of washout period [average for Visit 5 and 6])
Reported as:: Mean · Score on a scale

Key Secondary Endpoint: Change in Severity Based on Average CI-S
Score on a scale	Parent Study
Key Secondary Endpoint: Change in Severity Based on Average CI-S	-0.09 ± 0.39

SecondarySecondary Efficacy Endpoint: Individual Components of CI-CS

Time frame:: Baseline to end of treatment with IB1001 (Parent Study 6-weeks treatment); End of treatment with IB1001 to the end of post 6-week treatment washout.
Reported as:: Mean · Score on a scale

Secondary Efficacy Endpoint: Individual Components of CI-CS
Score on a scale	Parent Study
Treatment with IB1001	0.16 ± 0.81
Post-Treatment Washout	0.00 ± 1.18

SecondarySecondary Efficacy Endpoint: CI-CS Score Reclassified on a 3-Point Scale

The Clinical Impression of Change in Severity assessment will instruct the blinded rater to consider: compared to the first video, how has the severity of their performance on the 9 Hole Peg Test of the Dominant Hand (9HPT-D) or 8 Meter Walk Test (8MWT) changed (improved or worsened) in 6-weeks as observed in the second video? The Clinical Impression of Change in Severity is evaluated on a 7 point Likert scale (+3=significantly improved to -3= significantly worse). CI-CS scores \<0 were reclassified as worsened (-1), CI-CS scores 0 remained classified as not changed (0), and CI-CS scores \>0 were reclassified as improved (+1). When comparing Visit 4 versus Visit 2 and Visit 6 versus Visit 4, CI-CS scores \<0 were reclassified as worsened (-1), CI-CS scores 0 remained classified as not changed (0), and CI-CS scores \>0 were reclassified as improved (+1).

Time frame:: Baseline to end of treatment with IB1001 (Parent Study 6-weeks treatment); End of treatment with IB1001 to the end of post 6-week treatment washout
Reported as:: Count of participants · Participants

Secondary Efficacy Endpoint: CI-CS Score Reclassified on a 3-Point Scale
Participants	Parent Study
Treatment with IB1001 — -1 (Worsened)	6
Treatment with IB1001 — 0 (No Observable Change)	2
Treatment with IB1001 — +1 (Improved)	8
Post-treatment washout — -1 (Worsened)	7
Post-treatment washout — 0 (No Observable Change)	1
Post-treatment washout — +1 (Improved)	8

SecondarySecondary Efficacy Endpoint: CI-CS Score for the Non-Primary Anchor Test

Time frame:: CI-CS of the non-primary anchor test was evaluated, comparing the CI-CS of Visit 4 (end of treatment) versus Visit 2 (baseline) and of Visit 6 (end of washout) versus Visit 4 (end of treatment) as done for the primary anchor test.
Reported as:: Mean · Score on a scale

Secondary Efficacy Endpoint: CI-CS Score for the Non-Primary Anchor Test
Score on a scale	Parent Study
Treatment with IB1001	0.00 ± 1.07
Post-treatment washout	0.17 ± 1.03

SecondarySecondary Efficacy Endpoint: Change in the Scale for Assessment and Rating of Ataxia (SARA) Score [Schmitz-Hübsch Etal, 2006; Subramony, 2007]

The Scale for Assessment and Rating of Ataxia has 8 items that are related to gait, stance, sitting, speech, finger-chase test, nose-finger test, fast alternating movements, and heel-shin test. The range is 0-40 points, with a lower score representing neurological improvement and a higher score representing neurological worsening. Change values were calculated for each period, i.e. treatment with IB1001 (comparing the end of treatment (Visit 4) with baseline (Visit 2)) and post-treatment washout (comparing the end of washout (Visit 6) with the end of treatment (Visit 4)).

Time frame:: Baseline (Day 1) to end of treatment with IB1001 (Approximately Day 42); End of treatment with IB1001 (Approximately Day 42) to the end of post-treatment washout (Approximately Day 84)
Reported as:: Mean · Score on a scale

Secondary Efficacy Endpoint: Change in the Scale for Assessment and Rating of Ataxia (SARA) Score [Schmitz-Hübsch Etal, 2006; Subramony, 2007]
Score on a scale	Parent Study
Treatment with IB1001	-0.31 ± 3.47
Post-treatment washout	0.59 ± 2.99

SecondarySecondary Efficacy Endpoint: Spinocerebellar Ataxia Functional Index (SCAFI) [Schmitz-Hübsch et al, 2008]

Spinocerebellar Ataxia Functional Index (SCAFI) is composed of 8 Meter Walk Test, 9-Hole Peg Test of Dominant and Non-Dominant Hand (9HPT-D/9HPT-ND) (the 3 tests are timed assessments; each is done twice and values are averaged; the 8MWT and 9HPT-D and 9HPT-ND values are converted from times to rates, and the results expressed as a composite Z-score of each test relative to baseline) and the PATA rate (counted number how often a patient can repeat the syllables "PATA" within 10 seconds), a measure of speech performance. The scores of these 3 were transformed to Z-scores (=individual's average of both trials to perform the respective task -mean of study population at baseline) / SD of study population at baseline). A Z-score of 0 equates to the population mean at baseline. For all 3, higher Z-scores (above mean) mean better performance. The SCAFI total score was calculated as the arithmetic mean of the non-missing Z-scores for the 3. A higher total score means better performance.

Time frame:: Baseline (Day 1) to end of treatment with IB1001 (Approximately Day 42); End of treatment with IB1001 (Approximately Day 42) to the end of post-treatment washout (Approximately Day 84)
Reported as:: Mean · Score on a scale

Secondary Efficacy Endpoint: Spinocerebellar Ataxia Functional Index (SCAFI) [Schmitz-Hübsch et al, 2008]
Score on a scale	Parent Study
Treatment with IB1001	0.0583 ± 0.3384
Post-treatment washout	0.0157 ± 0.1923

SecondarySecondary Efficacy Endpoint: EuroQuol- 5 Dimension (EQ-5D) Quality of Life Scale

For posting, health-related quality of life based on the EQ-5D visual analogue scale (VAS) was presented as a secondary endpoint. EQ-5D VAS is a 0-100 scale where patients are asked to indicate their overall health, with a score of 0 indicating worst health and a score of 100 indicating best health.

Time frame:: Baseline (Day 1) to end of treatment with IB1001 (Approximately Day 42); End of treatment with IB1001 (Approximately Day 42) to the end of post-treatment washout (Approximately Day 84)
Reported as:: Mean · Score on a scale

Secondary Efficacy Endpoint: EuroQuol- 5 Dimension (EQ-5D) Quality of Life Scale
Score on a scale	Parent Study
Treatment with IB1001	4.9 ± 9.7
Post-treatment washout	-0.8 ± 10.5

SecondarySecondary Efficacy Endpoint: Clinical Global Impression of Severity (Treating Physician, Caregiver, Patient)

The Clinical Global Impression of Severity(CGI-S) evaluates the question "Considering your total (clinical) experience with this particular population, how ill is the patient (how ill are you) at this time?" based on answers from the treating physician, the caregiver, or the patients (if able). This was rated on the following seven-point scale: 1=normal, not at all ill; 2=borderline ill; 3=mildly ill; 4=moderately ill; 5=markedly ill; 6=severely ill; 7=among the most extremely ill the patient has been/I have ever been.

Time frame:: Visits of Parent study: Visit 1 (Day -14), Visit 2 (Day 1), Visit 3 (Day 28), Visit 4 (Day 42), Visit 5 (Day 70), and Visit 6 (Day 84).
Reported as:: Mean · Score on a scale

Secondary Efficacy Endpoint: Clinical Global Impression of Severity (Treating Physician, Caregiver, Patient)
Score on a scale	Parent Study
Treating physician: Visit 1	4.2 ± 1.1
Treating physician: Visit 2	4.2 ± 1.1
Treating physician: Visit 3	4.0 ± 1.1
Treating physician: Visit 4	4.0 ± 1.1
Treating physician: Visit 5	4.1 ± 1.0
Treating physician: Visit 6	4.1 ± 0.9
Caregiver: Visit 1	3.5 ± 2.0
Caregiver: Visit 2	3.1 ± 2.0
Caregiver: Visit 3	3.3 ± 1.6
Caregiver: Visit 4	2.9 ± 1.5
Caregiver: Visit 5	3.3 ± 1.7
Caregiver: Visit 6	3.4 ± 1.8
Patient: Visit 1	2.8 ± 1.8
Patient: Visit 2	2.3 ± 1.6
Patient: Visit 3	2.5 ± 1.7
Patient: Visit 4	2.4 ± 1.8
Patient: Visit 5	2.9 ± 1.8
Patient: Visit 6	2.9 ± 1.8

SecondarySecondary Efficacy Endpoint: Clinical Global Impression of Change (Treating Physician, Caregiver, Patient)

The Clinical Global Impression of Change assessed by the investigator is evaluated on a 7 point Likert scale ranging from 1='very much improved' to 7='very much worse' Change values were calculated for each period, i.e. treatment with IB1001 (comparing the end of treatment (Visit 4) with baseline (Visit 2)) and post-treatment washout (comparing the end of washout (Visit 6) with the end of treatment (Visit 4)).

Time frame:: Baseline (Day 1) to end of treatment with IB1001 (Approximately Day 42); End of treatment with IB1001 (Approximately Day 42) to the end of post-treatment washout (Approximately Day 84)
Reported as:: Mean · Score on a scale

Secondary Efficacy Endpoint: Clinical Global Impression of Change (Treating Physician, Caregiver, Patient)
Score on a scale	Parent Study
Treating physician: Treatment with IB1001	3.3 ± 0.9
Treating physician: Post-treatment washout	4.8 ± 0.9
Caregiver: Treatment with IB1001	3.1 ± 0.8
Caregiver: Post-treatment washout	4.7 ± 1.0
Patient: Treatment with IB1001	3.5 ± 0.9
Patient: Post-treatment washout	4.7 ± 1.1

Adverse events

Collected over For the parent study (treatment with IB1001 and Post-treatment washout): from signing of the informed consent form through to End of Study (Day 84, scheduled at 42 days post last IB1001dose); For the extension phase: from signing of the extension phase informed consent form through to End of Study for the extension phase (Day 767).. Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
Group	Deaths	Serious	Other
Treatment With IB1001	0/17 (0%)	1/17 (5.9%)	9/17 (52.9%)
Post-treatment Washout	0/17 (0%)	0/17 (0%)	2/17 (11.8%)
Extension Phase	1/13 (7.7%)	2/13 (15.4%)	11/13 (84.6%)

Most frequent serious events

Most frequent serious events
Event	Treatment With IB1001	Post-treatment Washout	Extension Phase
InfectionInfections and infestations	0/17	0/17	1/13
MastitisInfections and infestations	0/17	0/17	1/13
SeromaInjury, poisoning and procedural complications	0/17	0/17	1/13
Intraductal proliferative breast lesionNeoplasms benign, malignant and unspecified (incl cysts and polyps)	0/17	0/17	1/13
ErythemaSkin and subcutaneous tissue disorders	0/17	0/17	1/13
Peritoneal mesothelioma malignantNeoplasms benign, malignant and unspecified (incl cysts and polyps)	0/17	0/17	1/13
Gastrointestinal lymphomaNeoplasms benign, malignant and unspecified (incl cysts and polyps)	1/17	0/17	0/13

Most frequent other events

Showing 10 of 31

Most frequent other events
Event	Treatment With IB1001	Post-treatment Washout	Extension Phase
DiarrhoeaGastrointestinal disorders	0/17	1/17	3/13
NasopharyngitisInfections and infestations	1/17	0/17	2/13
Abdominal pain upperGastrointestinal disorders	2/17	1/17	0/13
Respiratory tract infectionInfections and infestations	1/17	0/17	1/13
Muscle spasmsMusculoskeletal and connective tissue disorders	0/17	1/17	1/13
BronchitisInfections and infestations	0/17	0/17	1/13
Candida infectionInfections and infestations	0/17	0/17	1/13
Corona virus infectionInfections and infestations	0/17	0/17	1/13
DysphagiaGastrointestinal disorders	0/17	0/17	1/13
VomitingGastrointestinal disorders	0/17	0/17	1/13

Baseline characteristics

Age, Continuous
Age, Continuous(Years)	Parent Study
Mean	23.3 ± 12.9

Sex: Female, Male
Sex: Female, Male(Participants)	Parent Study
Female	7
Male	10

Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)	Parent Study
Hispanic or Latino	2
Not Hispanic or Latino	15
Unknown or Not Reported	0

Study locations

4 sites

University of California - Los Angeles
Los Angeles, California 90095, United States
University of Giessen
Giessen, Germany
Hospital Universitario La Paz
Madrid, Spain, Spain
Royal Papworth Hospital NHS Foundation Trust
Cambridge, Cambridgeshire CB2 0AY, United Kingdom

References and documents

Publications

Hendrickx N, Mentre F, Hamdan A, Karlsson MO, Hooker AC, Traschutz A, Gagnon C, Schule R, Synofzik M, Comets E; ARCA Study Group, EVIDENCE-RND consortium. Comparing randomized trial designs to estimate treatment effect in rare diseases with longitudinal models: a simulation study showcased by Autosomal Recessive Cerebellar Ataxias using the SARA score. BMC Med Res Methodol. 2025 Jul 30;25(1):179. doi: 10.1186/s12874-025-02626-x. PubMed 40739200 ↗
Brueggemann A, Bicvic A, Goeldlin M, Kalla R, Kerkeni H, Mantokoudis G, Abegg M, Kolnikova M, Mohaupt M, Bremova-Ertl T. Effects of Acetyl-DL-Leucine on Ataxia and Downbeat-Nystagmus in Six Patients With Ataxia Telangiectasia. J Child Neurol. 2022 Jan;37(1):20-27. doi: 10.1177/08830738211028394. Epub 2021 Oct 7. PubMed 34620022 ↗
Churchill GC, Strupp M, Factor C, Bremova-Ertl T, Factor M, Patterson MC, Platt FM, Galione A. Acetylation turns leucine into a drug by membrane transporter switching. Sci Rep. 2021 Aug 4;11(1):15812. doi: 10.1038/s41598-021-95255-5. PubMed 34349180 ↗
Fields T, Patterson M, Bremova-Ertl T, Belcher G, Billington I, Churchill GC, Davis W, Evans W, Flint S, Galione A, Granzer U, Greenfield J, Karl R, Kay R, Lewi D, Mathieson T, Meyer T, Pangonis D, Platt FM, Tsang L, Verburg C, Factor M, Strupp M. A master protocol to investigate a novel therapy acetyl-L-leucine for three ultra-rare neurodegenerative diseases: Niemann-Pick type C, the GM2 gangliosidoses, and ataxia telangiectasia. Trials. 2021 Jan 22;22(1):84. doi: 10.1186/s13063-020-05009-3. PubMed 33482890 ↗

Study documents

Study protocol · Oct 5, 2023
Statistical analysis plan · Jun 18, 2024

Documents are hosted by the registry — open the source record to download them.

Registry details

Key details

Study ID: NCT03759678
Lead sponsor: IntraBio Inc
Responsible party: Sponsor
First posted: Nov 30, 2018
Start date: Jan 8, 2020
Primary completion: Feb 11, 2025
Completion: Oct 27, 2025
Results posted: Mar 25, 2026
Last update: Mar 25, 2026

Oversight

Data monitoring committee: Yes
FDA-regulated drug: Yes
FDA-regulated device: No

View the source record on ClinicalTrials.gov ↗

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