GW ANNOUNCES RESULTS OF NEUROPATHIC PAIN STUDIES

GW Pharmaceuticals has announced preliminary results from two Phase III studies of Sativex, its cannabinoid spray medicine, in peripheral neuropathic pain. These studies are part of a program to generate data for the future expansion of the use of Sativex in Europe beyond multiple sclerosis (MS) and into other pain conditions.

A multicenter, double-blind, randomized, placebo-controlled, parallel-group study in 246 patients examined the effect of Sativex in patients with neuropathic pain characterized by allodynia. Allodynia is the occurrence of pain in response to a normally nonpainful stimulus (clothes touching against the skin).

Patients in this study were being treated with a range of currently available analgesics, which were maintained during the course of the study. The results of this study confirm the efficacy of Sativex, for the responder analysis of the primary endpoint was statistically significantly in favor of Sativex. In addition, two of the key pain-related secondary efficacy endpoints, the Patient's Global Impression of Change and the assessment of sleep quality, were also statistically significantly in favor of Sativex.

Another multicenter, double-blind, randomized, placebo-controlled, parallel-group study in 297 patients examined the effect of Sativex in patients with painful diabetic neuropathy. Patients in this study were being treated with a range of currently available analgesics, which were maintained during the course of the study. In this study, patients taking Sativex showed a 30 percent mean improvement in pain scores. One-third of Sativex patients achieved a more than 50 percent improvement in pain.

However, the study results are difficult to interpret due to an abnormally large response in the placebo group. As such, although all outcome measures compared to placebo are in favor of Sativex, they do not reach statistical significance.

Sativex is approved and marketed in Canada for the symptomatic relief of central neuropathic pain in MS and is the subject of an ongoing regulatory submission in Canada for the relief of cancer pain.