Sativex effective in long-term treatment of MS neuropathic pain

UK-based GW Pharmaceuticals has published the results of a study in the Journal of Clinical Therapeutics which show that its cannabinoid Sativex provided effective long term treatment of central neuropathic pain in multiple sclerosis (MS) and that these benefits were obtained without any evidence of tolerance to the medicine.

Improvements in the pain scores for those patients who completed the extension trial showed sustained improvement over two years. At the end of the two-year treatment period, the mean pain score was 2.9/ 10 (mild pain). The mean pain score for all patients at entry into the initial short-term controlled trial was 6.5/ 10 (moderate). Side effects reported during the study were mild or moderate in severity.

Sativex is already approved as a prescription medicine in Canada for the relief of central neuropathic pain in MS. A study published in the peer-reviewed journal, Neurology, showed that Sativex was significantly superior to placebo in reducing pain and sleep disturbance. Sativex was deemed to be effective in short-term use, while the new study confirms that its effect in reducing pain and improving sleep is maintained over a prolonged period.

In addition to these completed trials, GW has recently completed patient recruitment in an additional phase III trial in MS neuropathic pain. The study has recruited 339 patients and is GW's largest clinical trial so far. The duration of treatment in the study is 14 weeks and results are expected in H1 2008.

Dr Stephen Wright, GW's R&D Director, said: "We believe that this study shows, in a setting that reflects normal clinical practice, that Sativex is able to meet a real medical need. The results add to what we know from short-term clinical trials, and we look forward to seeing the results of our ongoing pivotal study in the same condition in the first half of next year."