In a multicentre randomized trial, 339 patients with central neuropathic pain due to multiple sclerosis (MS) were randomized to receive either an oralmucosal spray containing THC and CBD (nabiximols) or placebo spray for 12 weeks, followed by an open-label and randomized-withdrawal phase for another 14 weeks. The primary outcome was at least 30% pain reduction, and secondary outcomes included time to treatment failure, Brief Pain Inventory, Global Assessment of Change, sleep quality, and adverse events. The cannabis spray was not significantly better at reducing pain compared to placebo.