LONDON – GW Pharma plc delivered positive results in a UK Phase III postmarketing study of Sativex, which will provide ballast for the launch of the cannabis-based product as a treatment for spasticity caused by multiple sclerosis in national markets across Europe and the Middle East.

The 121-patient Phase III placebo-controlled study was required by the UK regulator, the Medicines and Healthcare products Regulatory Agency, to evaluate if Sativex has any of the long-term adverse effects on cognitive function or mood that can be exhibited by recreational users of cannabis.

In the 12 month double-blind trial, there was a slight improvement in cognitive function in both Sativex and placebo groups, as assessed by the Paced Auditory Serial Addition Test, confirming that there was no evidence of long-term cognitive impairment in the Sativex group.

Similarly, change in mood, as assessed by the Beck Depression Inventory over 12 months was more or less identical in the Sativex and placebo groups, with no untoward effects on mood.

A series of secondary endpoints, of patient-, physician- and carer-assessed efficacy of Sativex in treating spasticity were all highly in favor of Sativex.

"I'm delighted to report these positive and highly reassuring results, showing no impact on cognition or mood in long-term use, and with further evidence of long-term efficacy," Stephen Wright, R&D director of Porton Down-based GW Pharma told a teleconference held to discuss the data and the company's third-quarter financial results.

In April, the UK government moved Sativex from Schedule 1 of the Misuse of Drugs Act to Schedule 4, in acknowledgement that the product has a low potential for abuse and low risk of diversion – and meaning Sativex can be prescribed in the UK with no restriction on supply, recording, storage or destruction. Now, the mood and cognition data will further drive the UK market.

The results on mood and cognition also will provide a fillip in the broader commercialization of Sativex, which currently is approved and on the market in 11 countries, with launches pending in 11 other national markets and regulatory filings in progress in nine further countries.

In addition, CEO Justin Gover said the positive data will accelerate development of Sativex in multiple sclerosis spasticity in the U.S., where GW Pharma recently submitted an investigational new drug application (IND). Bolstered by European Phase III data, "a single Phase III program" is expected to be sufficient for FDA approval, Gover said. He expects preparations for the Phase III to start before the end of 2013.

The results also will feed into the file on Sativex in treating cancer pain, with two pivotal U.S. Phase III trials recruiting currently, and top-line results expected in 2014. The cancer pain studies are funded by GW Pharma's partner Otsuka Pharmaceutical Co. Ltd., which holds exclusive commercialization rights in the U.S. The Tokyo-based company also is expected to fund Phase III U.S. development in multiple sclerosis spasticity.

At the same time, the Phase III mood and cognition study de-risks GW Pharma's non-Sativex cannabinoid pipeline. In total, the company has identified 70 cannabinoids and is exploring applications in a range of diseases.

Programs include GWP42003, which is in Phase IIa development in the treatment of ulcerative colitis with results due in the first half of 2014, and which also is expected to enter Phase I development in treating schizophrenia in 2014. Ahead of that, three other products that will commence clinical trials before the end of this year are GWP42006 for treating epilepsy; a Phase Ib/IIa trial of THC:CBD in the treatment of malignant glioma; and a Phase II dose-ranging trial of GWP42004, for Type II diabetes.

GW Pharma said there is emerging interest among pediatric specialists and patients' groups in the potential role of cannabidiol in treating intractable childhood epilepsy. Three INDs have been granted by the FDA to allow clinicians to treat patients with a formulation supplied by the company, and other clinicians have expressed interest in filing INDs in that indication.

A preclinical research collaboration with Otsuka, studying the use of cannabinoids in central nervous systems disorders and cancer, came to an end on June 30. Otsuka is now reviewing the data to decide whether to take anything forward into a new R&D agreement. GW has worldwide rights to all research and compounds that are not part of any future partnership.