Shares in UK group GW Pharmaceuticals were on the rise yesterday following the publication of promising results from a trial of its cannabis-based drug Sativex in cancer pain in a peer reviewed journal.

The multinational, randomised, placebo-controlled trial was designed to pit the effectiveness of Sativex (delta-9-tetrahydrocannabinol [THC] and cannabidiol) in improving pain against THC alone and a placebo, and involved 177 patients with advanced cancer who had failed to gain adequate pain relief with strong opioids.

The results, published in the Journal of Pain and Symptom Management, showed “a significant improvement” in the Sativex group compared with placebo in terms of pain improvement, but no significant difference between patients given THC and those given a placebo, providing “good evidence of the benefits which the presence of cannabidol confers on Sativex”, according to Dr Stephen Wright, GW’s R&D Director.

Overall, twice as many patients in the Sativex group achieved “a clinically meaningful improvement” in their pain score of 30% or more versus placebo, the firm said, and added that there was also a highly significant difference in responder rates between the two arms.

“These are very promising results for Sativex in an area where there is a real need for new approaches to treatment,” commented Professor Marie Fallon, Professor of Palliative Medicine, University of Edinburgh. “A number of patients with advanced cancer are not able to gain adequate pain relief from the existing medications, and the prospect that a new treatment may become available will be good news for many people”, she said.

Lead target
Cancer pain is the lead target indication for Sativex in the United States, and a follow-up Phase II/III trial is currently underway in collaboration with GW’s US licensing partner Otsuka Pharmaceutical Co, from which results are expected in Spring next year.

On this side of the pond, Sativex was filed for multiple sclerosis spasticity in Spain and the UK earlier this year - with the Medicines and Healthcare products Regulatory Agency acting as reference member state for Europe - and the company is anticipating a decision by the end of this year or early 2010.