GW Announces Positive Preliminary Results with its Cannabis Medicine in Phase III Neuropathic Pain Trial

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Jun 15, 2004

GW Pharmaceuticals announces positive preliminary results in a Phase III clinical trial with Sativex® in 125 patients with neuropathic (nerve damage) pain.

In the Phase III trial, a statistically significant improvement in comparison to placebo was achieved in pain as measured on a numerical rating scale (p<0.01), the primary endpoint of the study. In addition, positive results were obtained in the majority of secondary outcome measures including allodynia (p<0.05), pain disability index (p<0.01), quality of sleep (p<0.01), and patients’ global impression of change (p<0.01).

The trial was a multi centre double-blind, randomised, placebo-controlled parallel group study of Sativex in the treatment of peripheral neuropathic pain characterised by allodynia. In addition to study medication, all patients remained on their existing medication during the course of the trial.

Allodynia is the occurrence of pain in response to a normally non-painful stimulus (e.g. clothes touching against the skin). It is often intense and can occur in patients suffering from a range of conditions that damage the peripheral nerves (e.g. diabetes, post-herpetic neuralgia) and is a highly reliable marker of neuropathic pain.

In the trial, the safety profile was consistent to that shown in previous Sativex studies with adverse events being generally mild or moderate in intensity.

Dr Geoffrey Guy, Executive Chairman, said, “Neuropathic pain is one of the most difficult types of chronic pain to treat and available treatment options are limited. This Phase III trial adds further strong support to the body of evidence in neuropathic pain generated from GW’s earlier clinical trials. As in previous trials, the results obtained are over and above the effects of the patients’ existing drug treatments. We therefore believe that Sativex may present an important therapeutic advance for patients suffering from this condition.”

Sativex is currently the subject of regulatory applications in both the UK and Canada. In both countries, upon approval, Sativex will be exclusively marketed by Bayer HealthCare.

- Ends -


GW Pharmaceuticals plc

01980 557000

Dr Geoffrey Guy, Chairman

Justin Gover, Managing Director

Mark Rogerson, Press and PR

07885 638810

Weber Shandwick Square Mile

020 7067 0700

Kevin Smith / Sarah MacLeod

Notes to Editors


Sativex is a whole plant medicinal cannabis extract containing tetrahydrocannabinol (THC) and cannabidiol (CBD) as its principal cannabinoid components. The medicine is administered by means of a spray into the mouth.

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 1 per cent. of the world’s population suffers from neuropathic pain, including over 600,000 patients in UK.

Neuropathic pain can be difficult to diagnose and may be confused with nociceptive pain (caused by bodily injury - ‘visceral’ or ‘somatic’). The presence of allodynia can confirm that the pain experienced by the patient is truly neuropathic.

Neuropathic pain can be associated with many conditions including multiple sclerosis, stroke, cancer, spinal cord injury, physical trauma and peripheral neuropathy resulting from diabetes. It can also occur in patients who have previously suffered from shingles, a condition known as post-herpetic neuralgia.

Neuropathic pain is one of the most difficult types of chronic pain to treat. Since treatment options are limited, doctors often prescribe a combination of therapies in an attempt to relieve symptoms.

GW Neuropathic Pain Trials

GW has previously reported positive results from two neuropathic pain Phase III trials, in multiple sclerosis and in brachial plexus injury. A further Phase III trial is ongoing in patients with neuropathic pain arising from spinal cord injury.

Pain Disability Index (PDI)

The PDI consists of a collection of 7 rating scales designed to measure the degree to which several aspects of the patient’s life are disrupted by chronic pain. The scales are scored from 0 (no disability) to 10 (total disability), and cover the following domains: family/home responsibilities; social activity; sexual behaviour; life-support activities; recreation; occupation; self-care. PDI total score is obtained from the sum of these individual assessments.

This news release may contain forward-looking statements that reflect the Company's current expectations regarding future events, including the clinical development and regulatory clearance of the Company's products. Forward-looking statements involve risks and uncertainties. Actual events could differ materially from those projected herein and depend on a number of factors, including (inter alia), the success of the Company's research strategies, the applicability of the discoveries made therein, the successful and timely completion of clinical studies, including with respect to Sativex and the Company's other products, the uncertainties related to the regulatory process, and the acceptance of Sativex and other products by consumers and medical professionals.

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