The first patient has been enrolled in a phase 3 study of a treatment for type 1A Charcot-Marie-Tooth Disease (CMT1A) in the U.S., it was announced today (September 12).
Charcot-Marie-Tooth disease is a group of inherited conditions that damage the peripheral nerves and a treatment is being developed by French biopharmaceutical company, Pharnext.
The PREMIER Open Label Extension (PREMIER-OLE) study of PXT3003 enrolled the patient, who completed the double-blind, placebo-controlled PREMIER trial, in May 2021.
Encouraging data for Pharnext’s PXT3003
Burkhard Blank, chief medical officer at Pharnext said: “The decision to conduct a second open label extension study, after the PREMIER trial, was triggered by the encouraging data from our first, and ongoing, open-label extension study of the first PXT3003 phase 3.
“This has shown a sustained treatment benefit for patients with CMT1A treated with PXT3003 High Dose after five years.
“We look forward to generating additional long-term data to confirm the potential safety and efficacy of PXT3003 for these patients who currently have no treatment options.”
Debilitating disease
PXT3003 is the company’s lead program to treat CMT1A, a debilitating disease with currently no existing approved therapies.
The PREMIER trial, which recently completed enrollment with a total of 387 patients, is an international, randomized, double-blind, two-arm placebo-controlled, pivotal phase 3 study, where the primary objective is to evaluate the efficacy and safety of PXT3003 versus placebo in mild-to-moderate CMT1A patients, over a 15-month period.
Pharnext says the dose of PXT3003 tested in the PREMIER trial corresponds to the HD tested in the prior phase 3 clinical study, the PLEO-CMT trial, and the ongoing open-label extension phase 3 study, the PLEOCMT-FU trial.
The company says that it has been agreed with regulatory agencies, the primary efficacy endpoint will be the Overall Neuropathy Limitations Scale (ONLS), which measures functional motor disability.
Good safety profile
Recent data from the ongoing PLEOCMT-FU trial (open-label follow-up extension study of the first phase 3 study, the PLEO-CMT trial) announced in May 2022 showed a good safety profile and continuous treatment effect of PXT3003 measured on the ONLS after five years of total treatment time.
There are 123 patients with mild-to-moderate CMT1A are still on treatment with PXT3003 HD in the PLEOCMT-FU trial.
Xavier Paoli, chief operating officer at Pharnext, commented: “The PREMIER-OLE study provides patients who have completed our second pivotal phase 3 trial with the option to continue receiving treatment – all with PXT3003 HD – for this debilitating and progressive disease.
“We are committed to ensuring patients with CMT1A have continued access to PXT3003 High Dose, until the potential marketing authorization and subsequent commercialization.”