GW Pharmaceuticals’ share price took a knocking yesterday, falling by as much as 20% on the London Stock Exchange in the wake of reports that it had lost an appeal to be allowed to market Sativex (tetrahydrocannabinol plus cannabidiol) – its cannabis-derived drug for the treatment of multiple sclerosis-related pain – without having to conduct an additional clinical study.

The UK firm issued a statement noting the speculation, and confirmed that it had decided to appeal advice from the UK advisory body, the CSM, back in December that a further trial in MS spasticity would be required before a product licence for Sativex could be granted [[06/12/04e]]. The appeal was considered by the Medicines Commission at its meeting in mid-May, but GW says it has yet to be informed of any recommendations, nor has it received any communication from the regulator, the MHRA, since the meeting.

GW notes that, prior to the meeting, it was informed that it could take a number of weeks for the MHRA to formally notify the company of the outcome of the meeting, but confirmed that it would issue a further statement as soon it has received notification of the decision by the MHRA.

Sativex won approval in its first market of Canada in April [[20/04/05d]]. The product had originally been expected to get the green light from the UK regulator by the end of 2003 [[01/04/03e]], but has been dogged by delays [[03/12/03g]].