Pivotal Study of N-acetyl-L-leucine for CACNA1A

Not Applicable

Not yet recruiting

• Conditions: CACNA1A; Spinocerebellar Ataxia Type 6; Episodic Ataxia Type 2; Familial Hemiplegic Migraine-1
• Interventions: Drug: N-Acetyl-L-Leucine; Other: Placebo

• Registration Number: NCT07221292
• Lead Sponsor: IntraBio Inc

Brief Summary

A pivotal, randomized, double-blind, placebo-controlled, multi-center therapeutic study for patients age 4 and older with a confirmed diagnosis of CACNA1A. The objective of this study is to evaluate the safety, tolerability and efficacy of N-acetyl-L-leucine (IB1001) compared to standard of care.

Detailed Description

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 CACNA1A Disorders.

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.

Study Timeline

• Status Verified: 2025-10
• Study First Submitted: 2025-10-24
• Study First Submitted QC: 2025-10-24
• Last Update Submitted: 2025-10-24
• Study First Posted: 2025-10-27
• Last Update Posted: 2025-10-27
• Study Start: 2026-09-01
• Primary Completion: 2027-08-01
• Study Completion: 2028-11-01

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

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

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 CACNA1A Disorder (including patients with loss-of-function and fain-of-function mutations, e.g. Episodic Ataxia Type 2 (EA2), Familial Hemiplegic Migraine Type 1, Spinocerebellar Ataxia type C (SCA6), Developmental and Epileptic encephalopathy 42 (DEE42), Congenital ataxia or cerebellar hypoplasia due to a CACNA1A mutation) 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 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 who have ataxia symptoms which (outside of episodes, if applicable) fall within:

   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) CACNA1A disorder, 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).

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Exclusion Criteria

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

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 affect patient's mobility and, at the Investigator's discretion, interferes with their ability to perform study assessments.

8. Patients at non-EU trial sites 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.

   1. N-Acetyl-DL-Leucine (e.g. Tanganil®);
   2. N-Acetyl-L-Leucine (prohibited if not provided as IMP in the IB1001-304 trial);

9. Patients at EU trial sites who have had any of the following prohibited medication 42-days prior to Visit 1 (Baseline 1) and unwilling and/or not able to 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 IB1001-304 trial).

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
N-acetyl-L-leucine (IB1001)	N-Acetyl-L-Leucine	Oral administration (granule in a sachet for suspension in water, orange juice, or almond milk). Patients will receive a total daily dose of 2-4 g/day based on weight-tiered doses.
Placebo	Placebo	Oral administration (granule in a sachet for suspension in water, orange juice, or almond milk). Patients will receive a total daily dose of 2-4 g/day based on weight-tiered doses.

Primary Outcome Measures

Name	Time	Method
Scale for the Assessment and Rating of Ataxia	End of Period I (week 12) vs. End of Period 2 (week 24)	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.

Secondary Outcome Measures

Name	Time	Method
Spinocerebellar Ataxia Functional Index (SCAFI)	End of Period I (week 12) vs. End of Period 2 (week 24)	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.
Physician's / Caregiver's / Patient's Clinical Global Impressions (CGI)	End of Period I (week 12) vs. End of Period 2 (week 24)	The Clinical Global Impression of Improvement assessed by the investigator/caregiver/patient is evaluated on a 7 point Likert scale ranging from 1='very much improved' to 7='very much worse'
EuroQuol- 5 Dimension (EQ-5D) Quality of Life Scale	End of Period I (week 12) vs. End of Period 2 (week 24)	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.
Neuro Quality of Life - Upper Extremity Function (NeuroQOL-UEF)	End of Period I (week 12) vs. End of Period 2 (week 24)	The Neurology Quality of Life (NeuroQOL) Upper Extremity Function (UEF) scale is a self-report of health-related quality of life that measures the patient's ability to carry out various activities involving digital, manual, and reach-related functions, ranging from fine motor to self-care (activities of daily living)

Trial Locations

Locations (5)

Massachusetts General Hospital; 🇺🇸 Boston, Massachusetts, United States

The University of Texas Health (UT Health); 🇺🇸 Houston, Texas, United States

University of Cologne; 🇩🇪 Cologne, Germany

University of Giessen; 🇩🇪 Giessen, Germany

University Hospital Bern Inselspital; 🇨🇭 Bern, Switzerland