April has been a good month for UK drugmaker GW Pharmaceuticals - the company has now bagged an important US patent for its flagship product Sativex just weeks after hooking up Novartis as a marketing partner for the drug.

The United States Patent and Trademark Office has granted the firm a patent protecting the use of Sativex (delta-9-tetrahydrocannabinol and cannabidiol) as a treatment for cancer pain, providing all-important exclusivity until April 2025.

The patent is related to a method of treating cancer-related pain with a combination of the two principal cannabinoids in Sativex, further strengthening the intellectual property protecting the product, providing GW with "a unique position to benefit from the rich promise within the field of cannabinoid therapeutics," noted the firm's chairman Geoffrey Guy.

The drug is currently approved in the UK, Spain, Czech Republic, Canada and New Zealand as a treatment for multiple sclerosis spasticity, but cancer pain represents the lead indication for Sativex in the US, where it is partnered with Otsuka Pharmaceutical.

The Japanese drugmaker is stumping up the cash for current Phase III clinical trials programme assessing the drug in this setting.

Novartis deal

Earlier this month, the company signed a deal with Novartis under which the latter will commercialise and assist in regulatory filings for Sativex in Australia and New Zealand, Asia (excluding Japan, China and Hong Kong), the Middle East (excluding Israel/Palestine) and Africa for the reduction of severe spasticity associated with multiple sclerosis.

The deal sees GW pocket a $5 million upfront fee and the Porton Down, England-based group will also be eligible for an extra $29 million on the achievement of certain approval and commercial milestones, as well as royalties.