PXT3003 (baclofen / sorbitol / naltrexone)
An investigational treatment for Charcot-Marie-Tooth Disease.
The same compound appears under different names depending on the context. Here is how to identify PXT3003 (baclofen / sorbitol / naltrexone) wherever you encounter it, plus the key facts at a glance.
- Generic name
- PXT3003 (baclofen / sorbitol / naltrexone)
- Development code
- PXT3003
- Drug class
- Fixed-dose combination (PMP22-modulating)
- Manufacturer
- Pharnext (originally); Tianshili Group (current)
- How it's taken
- Taken by mouth as a liquid solution, twice daily.
A fixed-dose oral combination of three approved drugs in late-stage development for CMT1A, originally developed by Pharnext and now associated with the Tianshili Group. PXT3003 did not meet its primary endpoint in the Phase 3 PREMIER trial in adults, but a Tianshili (Tasly) company submitted a New Drug Application in China in April 2025, based on a separate Chinese Phase 3 trial in 176 patients that met its main goal. U.S. development status remains uncertain.
Where PXT3003 (baclofen / sorbitol / naltrexone) fits
Investigational, not approved in the U.S. or EU. Has a regulatory submission active in China. Patients with CMT1A who are interested should monitor announcements from the Tianshili Group, the Hereditary Neuropathy Foundation, and the CMT Research Foundation rather than relying on press coverage of the failed primary endpoint, since regulatory paths in different countries may diverge.
How PXT3003 (baclofen / sorbitol / naltrexone) works
CMT1A is caused by an extra copy of the PMP22 gene. The body ends up making too much of the PMP22 protein, which disrupts the myelin coating around peripheral nerves and causes the slow progression of weakness, sensory loss, and foot drop characteristic of CMT.
PXT3003 is a fixed-dose oral combination of three already-approved medicines: low-dose baclofen (a muscle relaxant), sorbitol (a sugar alcohol used as an inactive ingredient in many medications), and naltrexone (a drug usually used in addiction medicine). Pharnext used a network-pharmacology approach to identify that this specific combination, at low doses, can lower PMP22 expression and protect myelin in animal models. None of the three drugs alone produces the effect.
The PREMIER Phase 3 trial in adults with CMT1A did not meet its primary endpoint. Tianshili Group used additional data to support a separate New Drug Application in China in April 2025.
Mechanism: Fixed-dose oral combination of three approved drugs (low-dose baclofen, sorbitol, and naltrexone) repurposed and synergistically combined to lower PMP22 expression in nerve cells, intended to slow the demyelination that drives CMT1A.
Side effects and safety
Because PXT3003 is a combination of drugs that have been used safely for decades at higher doses, the individual safety profile of each component is well known. The combination has been studied in multiple Phase 2 and Phase 3 CMT1A trials. Reported side effects in clinical trials have generally been mild to moderate and consistent with what is known about baclofen, sorbitol, and naltrexone individually.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking PXT3003 (baclofen / sorbitol / naltrexone)
Taken by mouth as a liquid solution, twice daily. Specific dosing has been studied in the PREMIER Phase 3 trial.
Clinical trial results
[PREMIER (NCT04762758)](https://clinicaltrials.gov/study/NCT04762758) was the pivotal Phase 3 trial of PXT3003 in adults with CMT1A. The trial enrolled approximately 350 adults and ran a 15-month double-blind phase. The primary endpoint was a measure of overall function. PXT3003 did not meet its primary endpoint per the company. Earlier Phase 2/3 trials had shown improvements in exercise capacity and neuropathy severity, which contributed to the rationale for the pivotal study.
Development history
Pharnext, a French biotech, used a network-pharmacology platform to identify the PXT3003 combination as a CMT1A candidate. Multiple trials over a decade led to the Phase 3 PREMIER study. Pharnext faced financial difficulties and was later acquired or merged into the Tianshili Group, which has continued development. The Tianshili Group filed a New Drug Application in China in April 2025, based on its Chinese Phase 3 trial, which was published in iScience in 2026. The UK MHRA granted PXT3003 a Promising Innovative Medicine (PIM) designation, which is an early-access regulatory designation. As of 2026, the U.S. FDA path forward remains uncertain.
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Common questions about PXT3003 (baclofen / sorbitol / naltrexone)
▸What is PXT3003 (baclofen / sorbitol / naltrexone)?
A fixed-dose oral combination of three approved drugs in late-stage development for CMT1A, originally developed by Pharnext and now associated with the Tianshili Group. PXT3003 did not meet its primary endpoint in the Phase 3 PREMIER trial in adults, but a Tianshili (Tasly) company submitted a New Drug Application in China in April 2025, based on a separate Chinese Phase 3 trial in 176 patients that met its main goal. U.S. development status remains uncertain.
▸How does PXT3003 (baclofen / sorbitol / naltrexone) work?
CMT1A is caused by an extra copy of the PMP22 gene. The body ends up making too much of the PMP22 protein, which disrupts the myelin coating around peripheral nerves and causes the slow progression of weakness, sensory loss, and foot drop characteristic of CMT.
PXT3003 is a fixed-dose oral combination of three already-approved medicines: low-dose baclofen (a muscle relaxant), sorbitol (a sugar alcohol used as an inactive ingredient in many medications), and naltrexone (a drug usually used in addiction medicine). Pharnext used a network-pharmacology approach to identify that this specific combination, at low doses, can lower PMP22 expression and protect myelin in animal models. None of the three drugs alone produces the effect.
The PREMIER Phase 3 trial in adults with CMT1A did not meet its primary endpoint. Tianshili Group used additional data to support a separate New Drug Application in China in April 2025.
▸What are the side effects of PXT3003 (baclofen / sorbitol / naltrexone)?
Because PXT3003 is a combination of drugs that have been used safely for decades at higher doses, the individual safety profile of each component is well known. The combination has been studied in multiple Phase 2 and Phase 3 CMT1A trials. Reported side effects in clinical trials have generally been mild to moderate and consistent with what is known about baclofen, sorbitol, and naltrexone individually.
▸How is PXT3003 (baclofen / sorbitol / naltrexone) taken?
Taken by mouth as a liquid solution, twice daily. Specific dosing has been studied in the PREMIER Phase 3 trial.
▸Is PXT3003 (baclofen / sorbitol / naltrexone) FDA approved?
PXT3003 (baclofen / sorbitol / naltrexone) is currently in phase 3 clinical trials for Charcot-Marie-Tooth Disease. It has not yet received FDA approval.
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- U.S. National Library of Medicine — ClinicalTrials.gov. Pivotal Phase III Study to Assess the Efficacy and Safety of PXT3003 in CMT1A Patients (PREMIER). https://clinicaltrials.gov/study/NCT04762758
- Hereditary Neuropathy Foundation. Pharnext Announces PXT3003 Granted Promising Innovative Medicine (PIM) Designation by UK MHRA. https://www.hnf-cure.org/research/pharnext-pim/
- Hereditary Neuropathy Foundation. Pharnext Unveils Latest Progress of PREMIER Phase III Clinical Trial for CMT1A. https://www.hnf-cure.org/triad/triad-therapeutics/pharnext/pharnext-unveils-the-latest-progress-of-the-premier-phase-iii-clinical-trial-for-cmt1a/
- PubMed Central · 2026-08-26. A phase III clinical trial of PXT3003 in Chinese patients with Charcot-Marie-Tooth disease type 1A. https://pmc.ncbi.nlm.nih.gov/articles/PMC13544322/