Pharnext Raises 7.7M Euros to Develop PXT3003 Therapy for CMT1A

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by Mary Chapman |

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PXT3003, CMT1A

France-based Pharnext will use a capital raise of about 7.7 million euros ($8.4 million) to support the clinical development of PXT3003, the company’s experimental treatment for Charcot-Marie-Tooth disease type 1A (CMT1A).

Led by existing investors, the funding included some U.S. institutional investors and Pharnext management members.

“We are pleased to announce this capital raise, which demonstrates the strong, continued support of our historical shareholders,” Peter Collum, chief financial officer and chief business officer at Pharnext, said in a press release.

The funding will help finalize the study protocol for an upcoming Phase 3 trial of PXT3003, and fund other regulatory requisites placed by the U.S. Food and Drug Administration (FDA) and European Medicines Agency for continued treatment development.

A therapy combining approved treatments that act on the nervous system — baclofen, naltrexone, and sorbitol — PXT3003 is formulated as an oral solution to be taken twice daily. Previously, the treatment candidate received orphan drug and fast track designations from the FDA.

According to data from another Phase 3 trial and open-label extension study, PXT3003 was found to be safe and effective for CMT1A patients, improving clinical outcomes and stabilizing disease progression over the course of two years of treatment.

Called PLEO-CMT (NCT02579759), the 15-month, randomized, double-blind trial opened in late 2015 to evaluate the safety and efficacy of PXT3003 in 323 CMT1A patients, ages 16 to 65. Participants randomly received either a low or high dose of PXT3003, or a placebo, twice daily.

The study’s main goal was to gauge, over the course of a 12- and 15-month treatment period, changes in the extent of physical disability as measured by the Overall Neuropathy Limitation Scale (ONLS). In 2018, Pharnext announced the trial met its primary goal of showing major differences in ONLS between those who received the highest dose of PXT3003 and those treated with a placebo.

Participants who finished the trial were offered the opportunity to continue PXT3003 treatment by enrolling in an open-label extension study — PLEO-CMT-FU (NCT03023540).

After nine months, data indicated a general improvement in all treatment groups, compared to placebo groups. And, after switching to PXT3003, those who had originally received a placebo had a marked improvement of their ONLS scores.

Despite an unexpected treatment disruption — due to an issue with the high-dose PXT3003 formulation — that lasted five months on average, the studies’ compiled data showed that participants treated with both high- and low-dose formulations experienced ONLS score improvement or stabilization over nearly 25 months.

Extension study dosing will continue until PXT3003 is commercially available. Detailed study results are expected later this year.

Pharnext is now working towards a second Phase 3 trial of PXT3003. The company is in planning discussions with the FDA, which requested the additional study due to missing data caused by the unexpected formulation issue in PLEO-CMT. The study protocol, which the private placement will help fund, should be completed by June.

In addition, the company plans to use data from the new Phase 3 study to support the submission of a marketing authorization application for the treatment in Europe.