Phase III Trial Assessing the Efficacy and Safety of PXT3003 in CMT1A Patients — PREMIER  

Charcot-Marie-Tooth Disease Clinical Trial

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)

Status Active, not recruiting

Clinical Trial Summary

The study will consist of 2 periods: Double-blind Treatment and Open-Label Extension(OLE) Period.

-Double-blind Treatment Period - This will be randomized, double-blind, placebo-controlled part of the study which will be conducted in parallel groups, ie,1 group receiving the active treatment (PXT3003) and the other group receiving placebo.

Primary endpoint of the study will be assessed at Month 15.

-Open-label Extension (OLE) Period - All subjects completing Double-blind Treatment Period will be given an opportunity to enter the OLE Period of the study and receive the active treatment (PXT3003). The duration of the OLE Period will be based on Sponsor discretion, ie, Sponsor intends to keep the study open until the study drug PXT3003 is commercially available.

During this period, the long-term safety and efficacy of PXT3003 will be assessed as an exploratory objective.

Double-blind Treatment Period Objectives:

Primary:

To evaluate the efficacy of treatment with PXT3003 (a fixed-dose combination of [RS]-baclofen, naltrexone hydrochloride [HCl], and D-sorbitol) compared to placebo in subjects with Charcot-Marie-Tooth disease type 1A (CMT1A).

Secondary:

To evaluate the safety and tolerability of PXT3003 treatment in subjects with CMT1A.

Exploratory:

To characterize the relationship between plasma biomarkers and response to PXT3003 treatment.

OLE Period Objective:

Exploratory:

To evaluate the long-term safety and efficacy of PXT3003.

Clinical Trial Description

This is an international, multi-center, randomized, double-blind, placebo-controlled, parallel-group, Phase III study of PXT3003 in subjects with CMT1A. The study will be conducted at approximately 52 sites worldwide.

This study consists of Double-blind Treatment and OLE Periods.

Double-blind Treatment Period:

Eligible subjects will be screened and randomized in a 1:1 ratio to receive either oral PXT3003 or matching placebo, 10 mL, twice daily (BID) for 15 months. In order to maximize the tolerability of (RS)-baclofen for all randomized subjects, treatment will start with a half-dose (5 mL), taken BID (morning and evening with food) during the first 2 weeks, and then will be increased to a full-dose (10 mL), taken BID (morning and evening with food) until completion of the Treatment Period at Month 15.

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. Telephone contacts will take place at weeks 2 or 3, Month 1 and Month 2, and then monthly between subsequent in-person visits. A genotyping test for the Peripheral Myelin Protein 22 (PMP22) gene duplication will take place at the Screening Visit if it is not already documented for the subject. All subjects completing the Double-blind Treatment Period of the study will be given an opportunity to enter the OLE Period at Month 15 (Visit 6). Subjects not consenting to enter the OLE Period will have their last study visit (ie, Safety Follow-up Visit, Visit 7), 30 days after their last dosing day.

The primary outcome measures modified Overall Neuropathy Limitations Score(mONLS) and the 10-Meter Walk Test (10mWT), along with the Columbia Suicide Severity Rating Scale (C-SSRS) will be evaluated at each post-randomization in-person visit. The other secondary outcome measures, exploratory outcome, and safety/tolerability assessments will be evaluated as per Schedule of Activities (SOA). 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.

Planned duration for sites to enroll subjects: approximately 12 months, Subject Screening Period: 35 days, Subject Treatment Period: up to 15 months, Safety Follow-up Period (for subjects not entering the OLE Period): 30 days

OLE Period:

A subject entering the OLE Period (whether the subject was randomized to oral PXT3003 or matching placebo in the Double-blind Treatment Period) will start taking a half-dose of PXT3003 (5 mL) BID (morning and evening with food) during the first 2 weeks, and then a full dose of PXT3003 (10 mL) BID (morning and evening with food) throughout the OLE Period. The visits and assessments during the OLE Period are described in the SOA.

For subjects entering the OLE Period, Screening Day will occur on the same day as Visit 6 (Month 15) of the Double-blind Treatment Period. The duration of the Treatment Period will be based on Sponsor discretion. Sponsor intends to keep the study open until the study drug PXT3003 is commercially available. Safety Follow-up Period: 30 days ;

Related Conditions & MeSH terms

• Charcot-Marie-Tooth Disease
• Hereditary Sensory and Motor Neuropathy
• Nerve Compression Syndromes
• Tooth Diseases

• NCT number: NCT04762758
• Study type: Interventional
• Source: Pharnext S.C.A.
• Status: Active, not recruiting
• Phase: Phase 3
• Start date: March 30, 2021
• Completion date: April 19, 2024