Strong late-stage data for Sativex in MS pain

The UK's GW Pharmaceuticals has reported positive results from a placebo-controlled "randomized-withdrawal" study of its cannabis mouth spray, Sativex, in patients with neuropathic pain due to multiple sclerosis.

According to the firm, regulators have said that the study design is enough 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 late-stage MS neuropathic pain study, who continued to take it on an open-label basis for 12 weeks.

They were then randomized to Sativex or placebo for a further four weeks in a double-blinded manner. The prospectively defined primary efficacy endpoint of the study - the time to treatment failure - was statistically significantly in favor 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 treated patients maintained or improved their response while those who switched to placebo deteriorated.