Pharnext to Launch New Phase 3 Trial of PXT3003 for CMT1A

Pharnext to Launch New Phase 3 Trial of PXT3003 for CMT1A

Pharnext is planning a new Phase 3 clinical study to further explore the potential of PXT3003 in patients with Charcot-Marie-Tooth disease type 1A (CMT1A).

The decision to launch this new clinical trial was based on recommendations given by the U.S. Food and Drug Administration (FDA) after completing preliminary review and discussion of the pivotal Phase 3 PLEO-CMT study.

Despite the positive results of PLEO-CMT, the high-dose arm of the study was terminated early because of an “unexpected intercurrent formulation event” in one of the study groups, according to Pharnext. Based on this, the regulatory agency recommended that Pharnext run an additional trial to gather data that could ultimately support without doubt a New Drug Application for PXT3003 in CMT1A.

“The FDA acknowledged that CMT1A is a disease with high unmet medical need, granting Fast Track designation for PXT3003 in February 2019, and encouraged the Company to return to discuss a proposed study design,” Pharnext stated in a press release.

PXT3003 results from the combination of fixed doses of baclofen, naltrexone, and sorbitol — three already-approved medicines that act on the nervous system. The combo therapy is formulated to be administrated as an oral solution given twice a day.

The therapy has been granted orphan drug designation in the European Union and the United States, and priority review in China.

Preclinical studies demonstrated that PXT3003 can inhibit abnormally high levels of the PMP22 gene, the duplication of which causes CMT1A. It also increased the amount of the protective myelin layer around peripheral nerves, relieving neuromuscular symptoms associated with the disease.

The pivotal, double-blind PLEO-CMT trial (NCT02579759) was designed to assess the safety and efficacy of PXT3003 in 323 CMT1A patients, ages 16–65. The treatment was well-tolerated and eased disability compared with placebo in patients with mild to moderate disease.

Participants who completed the 15-month course of treatment in this Phase 3 trial will have the possibility to roll over to an extension study, the PLEO-CMT-FU (NCT03023540), to continue treatment with PXT3003 until it is commercially available. This ongoing study will provide long-term safety and efficacy data for PXT3003.

“We remain strongly confident in the potential of PXT3003 as a much-needed therapeutic option for patients with CMT1A, particularly given the consistent signal of efficacy observed across the clinical studies already performed and PXT3003’s strong safety profile to date,” Daniel Cohen, MD, PhD, co-founder and CEO of Pharnext, said. “We are fully committed to aligning with the FDA on the design of a clinical study as quickly as possible, in order to bring PXT3003 to U.S. patients with CMT1A.”

Pharnext is also continuing the development program for PXT3003 in CMT1A in Europe and China. The company is working to advance the registration path in Europe, and pursuing a development and registration path through its Chinese pharmaceutical partner, Tasly.

Total Posts: 13
Margarida graduated with a BS in Health Sciences from the University of Lisbon and a MSc in Biotechnology from Instituto Superior Técnico (IST-UL). She worked as a molecular biologist research associate at a Cambridge UK-based biotech company that discovers and develops therapeutic, fully human monoclonal antibodies.


  1. Lorraine Smith says:

    I live in Australia. My family has type 3x. Which affects from infancy. As CMT types stem from the same problem. Surely this medication could help all types. Could you please explain why it would not. Thank you.

  2. Patti O’Donnell says:

    Would like to be able to volunteer for any testing forCMT1A. The 1A runs in my family and would love to do whatever I can so that no more of my family members especially my grandkids will have to deal with this dreadful dz. sign me up!

    • Lorraine hotwagner says:

      Lorraine hotwagner I’m interested in any trial I’m 79 and getting weaker everyday can’t walk,stand and hardly able to get up or go down on my knees I’ll try anything

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