A Phase 3 clinical trial run by Pharnext for Charcot-Marie-Tooth disease Type 1A (CMT1A) has just been awarded 13.3 million dollars. $7.2 million comes from existing shareholders and $6 million comes from European investors.
This trial is investigating a therapy called PXT3003. It’s called PREMIER. This therapy is actually a combination of three different treatments that have previously been approved. These are naltrexone, sorbitol, and baclofen. Each of these acts on a different receptor within the nervous system, limiting production of the protein PMP22.
PXT3003 has already received Orphan Drug Designation from both the EMA and FDA, and Fast Track designation from the FDA.
PMP22 protein is excessively expressed in CMT1A patients because of a duplicate of the PMP22 gene. This leads to a loss of myelin coating around the nerve cells. Without this protective barrier, not only are the nerve cells exposed, but the efficiency of electric signals is also decreased.
PXT3003 leads to increased production of myelin by limiting PMP22 production.
This PREMIER trial will begin this month. The researchers hope to enroll a total of 35o patients across 50 trial sites globally. You can read more details on the trial specifics here.
The Phase 3 trial had 323 patients between the ages of 16 and 65. All participants received either PXT3003 (high or low dose) or placebo at random assignment. Each treatment was given orally twice each day for a total of 15 months.
187 individuals are in the open-label extension. These individuals will receive the treatment for 9 months. 130 of these patients are receiving a high dose. They have now been followed for over 2 years and will continue to be monitored.
This Phase 3 trial was very successful. The primary goal was met. Individuals who had been given the highest dose of the therapy had a significant reduction in scores on the Overall Neuropathy Limitation Scale. This treatment group also had a better walking speed.
Unfortunately, the trial had to be discontinued temporarily due to an issue with the manufacturing of the highest dose of the treatment. As a result, the FDA asked for a new Phase 3 trial. That is the purpose of PREMIER.
PREMIER will be very similar to PLEO-CMT. The treatment time, age of patients, and level of disease of participants (mild to moderate) will be the same. Thanks to the fix in the manufacturing issue of the high dose of the treatment, patients will receive either placebo or a high dose of PXT3003. The high dose now comes in a larger volume of liquid and dosing accuracy has been ensured.
Neuropathy scores and walking will again be measured. Additionally documented will be: changes in muscle strength, impairment, and disease severity.
You can read more about these trial updates and this investigative therapy here.