Evaluate the Maintenance of Effect After Long-term Treatment With Sativex® in Subjects With Symptoms of Spasticity Due to Multiple Sclerosis

This five week (one week baseline and four weeks randomised treatment period), multi-centre, placebo controlled, parallel group, randomized withdrawal study will evaluate the maintenance of effect after long-term treatment with Sativex® in subjects with symptoms of spasticity due to MS who have been receiving long-term benefit from treatment with Sativex®. Subjects will be selected from the Supply of Unlicensed Sativex® (SUS) or named patient supply programmes and must have been receiving Sativex® for at least 12 weeks prior to study entry. Following informed consent and screening, eligible subjects will enter the study (Visit 1, Day 1) and commence a seven day open label baseline period, before returning for a randomisation visit (Visit 2, Day 7), at which point they are randomised to receive either Sativex® or placebo (randomised withdrawal period). Subjects will return to the centre for an end of study visit at week five (Visit 3, Day 35) or earlier if they withdraw from treatment. Spasticity and sleep disruption review and dosing diaries will be completed each day from the start of the baseline period until completion or withdrawal.