GW Pharmaceuticals’ share price shot up by more than 14% during trading on the London Stock Exchange yesterday to a new 52-week high after the UK firm said that the Canada had become the first country to approve the company’s cannabis-based medicine, Sativex (tetrahydrocannabinol plus cannabidiol), for the relief of neuropathic pain in multiple sclerosis patients.

Dr Geoffrey Guy, GW’s executive chairman, said: “This event marks the world’s first approval of a cannabis derived medicine… We are now working with our Canadian marketing partner, Bayer, towards the launch of Sativex throughout Canada in late spring.”

Sativex was first filed with the Canadian regulators in May last year [[12/05/04e]], and the green light had been highly anticipated since Health Canada said late last year that GW had satisfied the conditions for approval [[21/12/04d]]. The product has also been submitted to the UK regulator, the Medicines and Healthcare products Regulatory Agency [[01/04/03e]]. However, the route to approval in this latter market has not been as smooth as in Canada – the country’s regulator has requested GW conduct an additional efficacy trial [[06/12/04e]].