WEX ANNOUNCES RESULTS OF OPIOID WITHDRAWAL STUDY

WEX Pharmaceuticals announced the results of the completed Phase IIa double-blind, placebo-controlled study of the efficacy and safety of tetrodotoxin in reducing withdrawal symptoms in methadone-maintained subjects.

The Phase IIa study used the opioid antagonist naloxone to induce opioid withdrawal symptoms in methadone-maintained subjects to evaluate the effects of tetrodotoxin on opioid withdrawal, and to serve as a model of spontaneous withdrawal which occurs when heroin or methadone use is discontinued.

The results of the current study suggest that the use of a four-day pre-treatment regimen of 30 micrograms of subcutaneous tetrodotoxin, two times a day, prior to the initiating of withdrawal symptoms with naloxone, does not alleviate the withdrawal symptoms, as assessed in 14 methadone-maintained subjects. However, the results are not conclusive since the study included a relatively small number of subjects with a large variation in response, a small carryover effect was observed from one treatment period to the next and in this pre-treatment study design tetrodotoxin was not administered while subjects were experiencing withdrawal symptoms.