Cannabis extract reduces cancer pain

The British firm GW Pharmaceuticals reported further positive clinical trial results with its cannabis-based medicine Sativex on 19 January and said a UK regulatory hearing on the drug was expected within six months. The company also announced it was looking at an eventual launch in the United States.

The trial was a multi centre placebo-controlled parallel group study including 177 patients. Participants had advanced cancer and were experiencing pain that was not responding adequately to other treatments. In addition to study medication, all patients remained on their analgesic medication during the trial. The study included two different study medications - Sativex (a cannabis extract containing THC and CBD) and a only THC-rich extract.

Sativex achieved a statistically significant improvement in pain in comparison to placebo. Approximately 40 per cent of patients on Sativex showed a greater than 30 per cent improvement in their pain. The other active arm of this study, GW’s THC extract did not show a significant effect in pain. This trial therefore suggests that Sativex is the more effective product for use in cancer pain.

GW’s under-the-tongue cannabis spray has won qualified approval in Canada for treatment of neuropathic pain in multiple sclerosis, but it is still awaiting a green light in Britain. UK approval is viewed as crucial, as it would open the door to the larger European market. The registration of the medicine has proved more complicated and lengthy than expected. UK marketing approval was originally expected by the end of 2003.