Neuropathic Pain

Neuropathic Pain is caused by damage to or dysfunction of the nervous system. It is usually chronic and accompanied by unpleasant burning or shooting sensations, or extreme sensitivity to touch. It is estimated that at least one per cent of the world’s population suffers from neuropathic pain.

Neuropathic pain is one of the most difficult types of chronic pain to treat and relief is often unsatisfactory or short-term. Since treatment options are limited, doctors often prescribe a combination of therapies in an attempt to relieve symptoms. It can be associated with many conditions including Multiple Sclerosis (MS), stroke, cancer, spinal cord injury, physical trauma, post-herpetic neuralgia (shingles), and peripheral neuropathy resulting from diabetes.

GW Sativex Neuropathic Pain Trials
In April 2005 GW announced its first regulatory approval (NOC/c) for Sativex® in Canada for the symptomatic relief of neuropathic pain in adults with Multiple Sclerosis.

GW has reported positive results from four Phase III neuropathic pain trials covering the following indications; central neuropathic pain in MS, allodynia and brachial plexus avulsion.  In these trials the patients maintained all their existing analgesic medication in addition to taking the study medication.  Therefore symptom relief obtained from Sativex was over and above any effect achieved by the patients existing analgesia.

All completed trials are listed below, together with associated publications where available:

• Central neuropathic pain

A double-blind, randomised, parallel group, placebo-controlled study of Sativex in central neuropathic pain in multiple sclerosis. (Rog DJ et al. Neurology. 2005;65:812-99).

A double-blind, randomised, three way crossover study comparing two different sublingual cannabis based medicines with placebo, in patients with chronic pain due to brachial plexus injury. (Berman et al Pain. 2004;112:299-306).

A randomised, double-blind, placebo-controlled, parallel group comparative study of the efficacy, safety and tolerability of sublingual cannabis based medicine (CBM) extracts and placebo in patients with intractable neuropathic pain associated with Spinal Cord Injury.

• Peripheral Neuropathic Pain

A double-blind, randomised, placebo-controlled, parallel group study of cannabis based medicine, in the treatment of peripheral neuropathic pain characterised by allodynia.

A double blind, randomised, placebo controlled, parallel group study of Sativex in the treatment of subjects with pain due to diabetic neuropathy.

A double blind, randomised, placebo controlled, parallel group study of Sativex in the treatment of subjects with peripheral neuropathic pain, associated with allodynia.

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