Sativex phase IIb pain trial results publication

Publication of full Sativex® phase IIb pain trial results

in official journal of the American Pain Society

London, UK; Tokyo, Japan; April 23 2012: GW Pharmaceuticals plc (AIM: GWP) and Otsuka Pharmaceutical Co., Ltd. today announce the publication in the Journal of Pain(1), the official journal of the American Pain Society, of the full results from a Phase IIb dose-ranging trial evaluating the efficacy and safety of Sativex® (USAN: Nabiximols) in the treatment of pain in patients with advanced cancer, who experience inadequate analgesia during optimized chronic opioid therapy.

This Phase IIb study was the first major trial carried out by GW and Otsuka Pharmaceutical as part of the development program aimed at securing regulatory approval for Sativex® from the Food & Drug Administration (FDA) in the United States. Top line results from this study were originally reported in March 2010 and a Phase III trials program has since commenced.

According to the publication's lead author, Dr. Russell K. Portenoy, Chairman of the Department of Pain Medicine and Palliative Care at Beth Israel Medical Center in New York City. "Many patients with advanced cancer do not attain adequate pain relief from an opioid regimen, or experience opioid side effects that limit the doses of opioids the patients can receive. The finding in this dose ranging study that Sativex® has potential analgesic efficacy as add-on therapy for pain due to advanced cancer that is poorly responsive to opioid therapy has great potential clinical relevance. Phase III confirmatory studies are strongly warranted and, if positive, may provide an opportunity to address a significant clinical challenge."

Two placebo-controlled multi-centre multinational Phase III cancer pain studies are now underway. Each Phase III trial is intended to recruit 380 patients. A third Phase III study is due to commence this year. The primary efficacy endpoint in the Phase III trials program is the continuous responder analysis (an analysis of all response levels characterized by percent improvement) of average daily pain from baseline to end of study as measured using a 0-10 Numeric Rating Scale (NRS). This Phase III trials program is funded by Otsuka.

(1) http://www.jpain.org/article/S1526-5900(12)00019-3/abstract

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Notes to Editors:

Sativex® in Cancer Pain

Treatment of pain in patients with advanced cancer, who experience inadequate analgesia during optimized chronic opioid therapy represents the initial target indication for Sativex® in the United States. All trials in this indication are being performed by GW and Otsuka under the terms of an exclusive license and development agreement to develop and market Sativex® in the US. Data generated from this trials program is also intended to be used by GW for regulatory submissions in the rest of the world.

In addition to the Phase IIb trial, a previous Phase IIa study has also been published in the Journal of Pain and Symptom Management, the Official Journal of the American Academy of Hospice and Palliative Medicine, the National Hospice and Palliative Care Organization, and the U.S. Cancer Pain Relief Committee (J Pain Symptom Manage.2010 Feb;39(2):167-79). In total, the Phase II program comprises over 500 patients.

Sativex® in Multiple Sclerosis

Sativex® is currently available as a prescription medicine for the treatment of spasticity associated with multiple sclerosis in the UK, Spain, Germany, Denmark, Canada and New Zealand.

Sativex® is indicated as treatment for symptom improvement in patients with moderate to severe spasticity due to multiple sclerosis (MS) who have not responded adequately to other anti-spasticity medication (i) and who demonstrate clinically significant improvement in spasticity related symptoms during an initial trial of therapy.1

About Otsuka Pharmaceutical Co., Ltd.

Founded in 1964, Otsuka Pharmaceutical Co., Ltd. is a global healthcare company with the corporate philosophy: 'Otsuka-people creating new products for better health worldwide.' Otsuka researches, develops, manufactures and markets innovative and original products, with a focus on pharmaceutical products for the treatment of diseases and consumer products for the maintenance of everyday health. Otsuka is committed to being a corporation that creates global value, adhering to the high ethical standards required of a company involved in human health and life, maintaining a dynamic corporate culture, and working in harmony with local communities and the natural environment.

Otsuka Pharmaceutical Co., Ltd. is a wholly owned subsidiary of Otsuka Holdings Co., Ltd., the holding company for the Otsuka Group. The Otsuka Group has business operations in 23 countries and regions around the world, with consolidated sales of ¥1,090.2 billion for fiscal year 2010.

For more information, please visit www.otsuka.co.jp/en.

About GW

GW was founded in 1998 and listed on the AIM, a market of the London Stock Exchange, in June 2001. Operating under license from the UK Home Office, the company researches and develops cannabinoid pharmaceutical products for patients who suffer from a range of serious ailments, in particular multiple sclerosis and cancer pain. GW has assembled a large in-house scientific team with expertise in cannabinoid science as well as experience in the development of both plant-based prescription pharmaceutical products and medicines containing controlled substances. GW occupies a world leading position in cannabinoids and has developed an extensive international network of the most prominent scientists in the field. For further information, please visit www.gwpharm.com

This news release may contain forward-looking statements that reflect GWs current expectations regarding future events, including development and regulatory clearance of the GW's products. Forward-looking statements involve risks and uncertainties. Actual events could differ materially from those projected herein and depend on a number of factors, including (inter alia), the success of the GW's research strategies, the applicability of the discoveries made therein, the successful and timely completion of uncertainties related to the regulatory process, and the acceptance of Sativex® and other products by consumer and medical professionals.

(i) Sativex® Summary of Product Characteristics, 2011.