Additional Study Information: Charcot-Marie-Tooth type 1A (CMT1A) disease is a rare, slowly progressing and debilitating hereditary condition commonly causing weakness of muscles in the feet and lower parts of the legs. There is currently no approved drug to cure CMT1A disease, and the available treatments commonly target the pain and inflammation associated with the disease. In order to promote nerve protection, Pharnext Laboratories has developed this investigational drug, PXT3003, which is a combination of very low doses of 3 substances; baclofen, naltrexone and sorbitol. Individually, these are well established medicines for more than 30 years.While higher doses of these medicines have been used to treat many indications, very low doses are combined to form PXT3003. The combined actions of the three substances at low dose are expected to improve the function of the myelin sheath, improve signal transmission between nerve cells and relieve the symptoms of the disease as demonstrated in previous Pharnext research studies. The objective of this study is to test two different doses of PXT3003 (Dose 1 and Dose 2) vs. a placebo and to confirm the effectiveness and safety of PXT3003 over a larger patient population.