Canadians For Safe Access  
grassroots, action-oriented patient rights
Home >> Research >> Multiple Sclerosis

Positive Sativex® Study Confirms Long Term Efficacy in MS Neuropathic Pain

Positive Sativex® Study Confirms Long Term Efficacy in MS Neuropathic Pain

Results Support Design of Ongoing Phase III MS Spasticity Study

Porton Down, UK, 8 September 2008: GW Pharmaceuticals plc (GWP:AIM) announces positive results from a placebo-controlled "randomized withdrawal" study of Sativex® in patients with neuropathic pain due to Multiple Sclerosis (MS). This study design is described by regulators as being sufficient to satisfy the need for long-term efficacy data.

This randomized withdrawal study evaluated 42 MS patients with central neuropathic pain who had previously been in a Sativex Phase III MS neuropathic pain study and who continued to take Sativex on an open label basis for 12 weeks. They were then randomized to Sativex or placebo for a further 4 weeks in a double-blinded manner. During the randomized period, patients were not permitted to adjust their dose. The purpose of this blinded 4-week "randomized withdrawal" study was to assess the maintenance of pain control in patients who remain on Sativex versus those who switch to placebo.

In the patients who were randomized to Sativex pain scores remained stable. In the patients randomized to placebo, pain and sleep scores deteriorated. The prospectively defined primary efficacy endpoint of the study - the time to treatment failure - was statistically significantly in favour of Sativex (p=0.036). The difference between Sativex and placebo was also significant for mean pain score (p=0.028) and sleep quality (p=0.015). The results of all other symptom-related endpoints showed that Sativex patients maintained or improved their response whilst the symptoms of those who switched from Sativex to placebo worsened in the 4 weeks following cessation of active treatment. During the randomized withdrawal period, there were 2 patients with adverse events on Sativex, and 5 on placebo. One patient on placebo withdrew from the study. There was no evidence of any withdrawal syndrome.

Until now, all the evidence for long-term maintenance of efficacy of Sativex has come from long-term open-label exposurei. The results reported today confirm in the context of a placebo-controlled double-blind study that efficacy is indeed maintained in long-term use.

The results of this study are of further significance to GW since the design bears important similarities to the ongoing Phase III MS spasticity study requested by the UK regulator prior to granting approval for Sativex. This ongoing Phase III study involves all patients receiving Sativex for 4 weeks, following which Sativex responders are randomized to continue on Sativex or switch to placebo for a further 12 weeks. This study is due to report results in Q1 2009 with a regulatory submission targeted for H1 09.

Dr Stephen Wright, GW's R&D Director, said: "This is the first placebo-controlled study showing that Sativex provides long term efficacy for MS patients with neuropathic pain and supplements previously published open-label studies. In addition, these results support the design of the ongoing Phase III trial in MS spasticity. It is encouraging to note that if the difference between Sativex and placebo achieved in the results today are replicated in the ongoing Phase III MS spasticity study, this Phase III study will meet its objectives."

Study: Cannabis Helps Spasticity/bladder in MS Patients

Monday, October 16 2006 @ 01:02 AM EDT

Science: Sativex effective in spasticity and bladder problems of patients with multiple sclerosis

IACM via BBSNews 2006-10-16 -- Results of two studies with the cannabis extract Sativex conducted in the United Kingdom were presented at the 22nd Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), which took place in Madrid, Spain, from 27 - 30 September.

In the first study 337 participants with severe levels of spasticity received either Sativex or placebo for 15 weeks. Spasticity of patients who received cannabis and complied with the study protocol was significantly reduced compared to placebo. In this group of patients 36 per cent of subjects achieved at least a 30 per cent improvement in spasticity. There was a trend in favour of Sativex for other symptoms including sleep and quality of life.

In the second study 135 subjects with bladder problems due to multiple sclerosis received either Sativex or placebo for ten weeks. There was a significant reduction in the number of voids per day and during the night, and patients rated cannabis significantly superior to placebo with regard to the severity of their bladder symptoms.

See other documents at:

GW Pharmaceuticals, Press Releases The MS spasticity study and Meta-analysis of the effects of Sativex® on spasticity associated with multiple sclerosis