for people ages 16-65 (full criteria)
at Sacramento, California and other locations
study started
estimated completion
Principal Investigator
by Lisa Williams



The purpose of this study is to determine whether PXT3003 is effective and safe in the treatment of Charcot-Marie-Tooth disease - Type 1A. This double-blind study will assess in parallel groups 1 dose of PXT3003 compared to Placebo in CMT1A patients treated for 15 months.

Official Title

A Multi-center, Randomized, Double-blind, Placebo Controlled Phase III Study to Assess the Efficacy, Safety, and Tolerability of PXT3003 in Charcot-Marie-Tooth Type 1A (CMT1A)


This international, multi-center, randomized, double-blind, placebo-controlled, Phase III clinical study is designed to evaluate PXT3003 versus placebo in male and non-pregnant female subjects with genetically confirmed CMT1A of mild-to-moderate severity (CMTNS-V2 score >2 and ≤18) aged 16 to 65 years. The study will be conducted in approximately 48 sites worldwide. Genetically confirmed CMT1A subjects will be screened (approximately 500 subjects assuming a 30% screen failure rate) and randomized in a 1:1 ratio to receive either oral PXT3003 daily or matching placebo for 15 months. A total of approximately 350 subjects will be enrolled. Visits will take place at Screening (up to -35 days), Baseline (Day 1), and Months 3, 6, 9, 12, and 15. Randomization will occur at the Baseline (Day 1) Visit. Telephone contacts (TC) will take place at Weeks 2 or 3, Month 1 and 2, and then monthly between subsequent in-person visits. A Safety follow-up visit will be conducted at Month 16. Subjects will receive in-clinic dosing of study medication at visits on Day 1 and Months 6, 12, and 15. Study medication will be dispensed for outpatient dosing on Day 1 and Months 3, 6, 9, and 12. During outpatient dosing, subjects will complete the Study Medication Diary using an application on their tablet, phone, or computer. The Study Medication Diary will be evaluated, along with returned unused study medication, as part of study drug compliance at visits at Months 3, 6, 9, 12, and 15. The primary outcome measure (mONLS) and the 10-Meter Walk Test (10mWT), along with the Columbia Suicide Severity Rating Scale (C-SSRS) will be evaluated at each post-Screening visit. The other secondary outcome measures, exploratory outcome, and safety/tolerability assessments will be evaluated as per Schedule of Activities (SOA). A Safety Follow-Up Visit will take place 30 days (Month 16) after the active treatment period ends (Month 15). A Data Safety and Monitoring Board (DSMB) will meet on a scheduled basis throughout the study to review safety data and will reconvene on an ad hoc basis as necessary.


Charcot-Marie-Tooth Disease Charcot Marie Tooth Type 1 Peripheral Neuropathy PXT3003 Tooth Diseases Nerve Compression Syndromes Hereditary Sensory and Motor Neuropathy Naltrexone Baclofen Sorbitol (RS)-baclofen, naltrexone hydrochloride and D-sorbitol


You can join if…

Open to people ages 16-65

  1. Male and non-pregnant female subjects, aged 16 to 65 years with a genetically proven diagnosis of CMT1A.
  2. Able to provide written informed consent/assent and comply with study procedures.
  3. Mild-to-moderate severity assessed by a CMTNS-V2 score >2 and ≤18.
  4. Muscle weakness in at least foot dorsiflexion on clinical assessment.
  5. Ulnar nerve motor conduction time of at least 15 m/s.
  6. Stable dose of prescribed psychoactive drugs (eg, antidepressants, stimulants, tranquilizers, anti-epileptics) for at least 4 weeks prior to randomization, which is not planned to be changed.
  7. Stable dose of prescribed or 'over-the-counter' analgesic medications (eg, paracetamol/acetaminophen, nonsteroidal anti-inflammatory drugs) for at least 2 weeks prior to randomization, which is not planned to be changed.
  8. If female, subject must be: (a) surgically sterilized via hysterectomy, bilateral oophorectomy, or bilateral tubal ligation; or (b) of childbearing potential and using a birth control method such as:
  9. Combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation:
  10. Oral
  11. Intravaginal
  12. Transdermal
  13. Progestogen-only hormonal contraception associated with inhibition of ovulation:
  14. Oral
  15. Injectable
  16. Implantable
  17. Intrauterine device
  18. Intrauterine hormone-releasing system
  19. Bilateral tubal occlusion
  20. Vasectomized partner
  21. Sexual abstinence or (c) Of non-childbearing potential (ie, postmenopausal for at least 1 year)
  22. If male, the subject must have had a vasectomy or must use a reliable method of birth control with their partner or total abstinence from sexual intercourse. The subject must agree to continue using their selected method of birth control with their sexual partner during the study and for 120 days after study completion.

You CAN'T join if...

  1. Subjects previously enrolled in any PXT3003 study.
  2. Subjects living in the same household and enrolled in a PXT3003 study (due to potential lack of adequate storage for study material, risk of mixing treatments and potential unblinding).
  3. CMT of any subtype other than 1A.
  4. ONLS score of 0.
  5. Known clinically significant motor or sensory abnormalities secondary to a different neurological cause (eg, diabetes, alcohol, vascular, autoimmune, neoplastic, neurodegenerative, human immunodeficiency virus, etc.).
  6. Subjects who have had any surgery or have a concomitant disorder (eg, severe arthrosis) that reduces the mobility of the ankle making it, in the opinion of the investigator, difficult to assess the efficacy of the treatment.
  7. Known peripheral neuropathy, myopathy, or neuromuscular disorder of any other kind.
  8. Any other clinically significant and/or uncontrolled medical condition that, in the opinion of the investigator, could be a confound or may preclude successful participation or completion of the study.
  9. Known hypersensitivity or intolerance to baclofen, naltrexone, or sorbitol.
  10. . Concomitant treatments including but not limited to baclofen, naltrexone, sorbitol (pharmaceutical form), opioids, and potentially neurotoxic drugs such as amiodarone, chloroquine, and chemotherapeutics capable of inducing peripheral neuropathy. Subjects able to stop these medications at least 2 weeks before randomization and for the study duration may be included.
  11. . History of porphyria.
  12. . Diagnosis or history of substance use disorder by Diagnostic and Statistical Manual of Mental Disorders-5th Edition criteria within the past 12 months.
  13. . Medical or recreational use of marijuana in the 3 months prior to the Screening Visit.
  14. . Active suicidality (eg, any suicide attempts within the past 12 months or any current suicidal intent, including a plan, as assessed by the C SSRS score of "YES" on questions 4 or 5; and/or based on clinical evaluation by the investigator).
  15. . Currently active major depression, as determined by a Beck Depression Inventory-II (BDI-II) score ≥20.
  16. . Currently lactating, pregnant, or planning on becoming pregnant during the study.
  17. . Alanine aminotransferase or aspartate aminotransferase levels greater than 2 times the upper limit of normal.
  18. . Significant renal impairment as determined by glomerular filtration rate of less than 50 mL/min.
  19. . Subject has participated in an investigational drug or device study within 30 days prior to the Screening Visit or plans to participate in an investigational drug or device study during the course of this study.
  20. . Subject is a dependent and/or relative of the Sponsor or Principal Investigator.


  • UC Davis Health Department of Physical Medicine and Rehabilitation accepting new patients
    Sacramento California 95817 United States
  • Cedars-Sinai Medical Center accepting new patients
    Los Angeles California 90048 United States

Lead Scientist at UC Davis

  • Lisa Williams
    Assistant Professor, Physical Medicine and Rehabilitation.


accepting new patients
Start Date
Completion Date
Pharnext SA
Sign up for this study
Phase 3
Study Type
Last Updated