BioWorld International Correspondent

LONDON - Just three weeks after getting a thumbs down from UK regulators, GW Pharmaceuticals plc received notice of approval of its cannabis extract Sativex in Canada.

Sativex, a sublingual spray, will be approved initially for the relief of neuropathic pain in multiple sclerosis, becoming the first cannabis-based prescription medicine.

A company spokeswoman told BioWorld International the conditions attached to the qualifying notice are in line with standard guidance.

"There are no different requirements related to the nature of the product; it is now a matter of some form filling, which is expected to take around two months," she said.

GW's shares lost a third of their value at the beginning of December after the rejection in the UK, falling by 35.5 pence to £1.06 (US$2.04). The price rose 8.5 pence to £1.13 on news of the pending Canadian approval.

Salisbury-based GW is required to respond and accept the conditions within 30 days. Health Canada then has 30 days to review the response and proceed to finalize the marketing authorization early in 2005.

Sativex, which contains the active ingredients tetrahydrocannabinol and cannabidiol, will be marketed in Canada by Bayer Healthcare. Following the initial approval in multiple sclerosis, GW plans further applications in additional indications, including pain caused by other diseases.

About 50,000 people in Canada are diagnosed with multiple sclerosis.

The rejected UK application was for the use of Sativex to treat spasticity in multiple sclerosis, an indication GW prioritized over neuropathic pain caused by the disease on the advice of regulators. Based on patients' own assessments, there was a statistically significant effect on spasticity in Phase III, but the regulators said there was no evidence the effect was of clinical relevance and asked for another trial based on an undisclosed non-subjective endpoint.

GW put aside positive results in five other Phase III trials to follow the advice of getting approval in spasticity, and said it will contest the decision in the UK.

Unlike the UK review, which dragged on for 22 months, the Canadian review was completed in seven months.

In a dig at UK regulators, Geoffrey Guy, executive chairman, said he was "grateful" for the rapid response in Canada, adding that it will be a major milestone for people with multiple sclerosis who have long awaited a prescription cannabis medicine.

"We believe that the pragmatism shown by Health Canada in their review reflects a welcome recognition of the clinical need in multiple sclerosis patients for Sativex," he said.