Positive Sativex® Study Confirms Long Term Efficacy in MS Neuropathic Pain

08/09/2008

Results Support Designof Ongoing Phase III MS Spasticity Study

Porton Down, UK, 8 September 2008: GW Pharmaceuticals plc (GWP:AIM) announces positive results from a placebo-controlled “randomized withdrawal” study of Sativex® in patients with neuropathic pain due to Multiple Sclerosis (MS). This study design is described by regulators as being sufficient to satisfy the need for long-term efficacy data.

This randomized withdrawal study evaluated 42 MS patients with central neuropathic pain who had previously been in a Sativex Phase III MS neuropathic pain study and who continued to take Sativex on an open label basis for 12 weeks. They were then randomized to Sativex or placebo for a further 4 weeks in a double-blinded manner. During the randomized period, patients were not permitted to adjust their dose. The purpose of this blinded 4-week “randomized withdrawal” study was to assess the maintenance of pain control in patients who remain on Sativex versus those who switch to placebo.

In the patients who were randomized to Sativex pain scores remained stable. In the patients randomized to placebo, pain and sleep scores deteriorated. The prospectively defined primary efficacy endpoint of the study - the time to treatment failure - was statistically significantly in favour of Sativex (p=0.036). The difference between Sativex and placebo was also significant for mean pain score (p=0.028) and sleep quality (p=0.015). The results of all other symptom-related endpoints showed that Sativex patients maintained or improved their response whilst the symptoms of those who switched from Sativex to placebo worsened in the 4 weeks following cessation of active treatment. During the randomized withdrawal period, there were 2 patients with adverse events on Sativex, and 5 on placebo. One patient on placebo withdrew from the study. There was no evidence of any withdrawal syndrome.

Until now, all the evidence for long-term maintenance of efficacy of Sativex has come from long-term open-label exposurei. The results reported today confirm in the context of a placebo-controlled double-blind study that efficacy is indeed maintained in long-term use.

The results of this study are of further significance to GW since the design bears important similarities to the ongoing Phase III MS spasticity study requested by the UK regulator prior to granting approval for Sativex. This ongoing Phase III study involves all patients receiving Sativex for 4 weeks, following which Sativex responders are randomized to continue on Sativex or switch to placebo for a further 12 weeks. This study is due to report results in Q1 2009 with a regulatory submission targeted for H1 09.

Dr Stephen Wright, GW’s R&D Director, said: “This is the first placebo-controlled study showing that Sativex provides long term efficacy for MS patients with neuropathic pain and supplements previously published open-label studies. In addition, these results support the design of the ongoing Phase III trial in MS spasticity. It is encouraging to note that if the difference between Sativex and placebo achieved in the results today are replicated in the ongoing Phase III MS spasticity study, this Phase III study will meet its objectives.”

Enquiries:

GW Pharmaceuticals plc (Today) + 44 20 7831 3113
Dr Geoffrey Guy, Executive Chairman (Thereafter) + 44 1980 557000
Justin Gover, Managing Director

Financial Dynamics + 44 20 7831 3113
David Yates / John Dineen



Notes to Editors

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 pain and other neurological symptoms. GW has assembled a team of over 100 scientists with extensive experience in developing 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.

iRog DJ et al. Clinical Therapeutics. 2007; 29: 2068-2079

Expert Opinion Paper - National MS Society Makes Recommendations Regarding Therapeutic Use Of Cannabis

Washington, DC: Cannabis has the potential to treat symptoms of multiple sclerosis as well as limit the progression of the disease, according to an expert opinion paper published by the US National Multiple Sclerosis Society. However, the Society stopped short of recommending that MS patients use the drug medicinally.

“Although it is clear that cannabinoids have potential both for the management of MS symptoms such as pain and spasticity, as well as for neuroprotection, the Society cannot at this time recommend that medical marijuana be made widely available to people with MS for symptom management,” the Society concludes. “This situation might change, should better data become available that clearly demonstrate benefit.”

The Society recommends that future clinical trials focus on methods of cannabinoid administration that deliver the drug to the bloodstream rapidly, such as vaporization.

The Society also recommends clinical trials be performed to investigate and quantify cannabis’ potential to slow disease progression, citing “anecdotal reports from patients … that cannabis reduces the frequency of their MS attacks.”

Investigators at Plymouth’s Peninsula Medical School in Britain recently announced that they had recruited nearly 500 MS patients for a three-year clinical trial assessing whether the use of oral THC can significantly slow the onset of multiple sclerosis.

Clinical data reported in 2006 from an extended open-label study of 167 multiple sclerosis patients found that the use of whole plant cannabinoid extracts relieved symptoms of pain, spasticity, and bladder incontinence for an extended period of treatment (mean duration of study participants was 434 days) without requiring subjects to increase their dose.

Results from a separate two-year open label extension trial in 2007 also reported that the administration of cannabis extracts was associated with long-term reductions in neuropathic pain in select MS patients. On average, patients in the study required fewer daily doses of the drug and reported lower median pain scores the longer they took it.

Commenting on the MS Society report, NORML Deputy Director Paul Armentano said: “The MS Society’s recommendations are a positive step, but they don’t go far enough. Surveys indicate that as many as one out of two MS patients use cannabis therapeutically, yet this report does nothing to challenge these patients legal status as criminals.”



For more information, please contact Paul Armentano, NORML Deputy Director, at: paul@norml.orgThis e-mail address is being protected from spam bots, you need JavaScript enabled to view it

Full text of the MS Society paper, “Recommendations Regarding the Use of Cannabis in Multiple Sclerosis”. Additional information on cannabinoids and multiple sclerosis is available from NORML. The paper can also be downloaded from the NMSS web site in PDF format by clicking on the title of this posting.

http://norml.org/

Sativex® Commences US Phase II/III Clinical Trial in Cancer Pain

26/11/2007

London, UK; Tokyo, Japan; 26 November 2007: GW Pharmaceuticals plc (AIM: GWP) and Otsuka Pharmaceutical Co., Ltd. today announced that the first US Phase II/III dose-ranging trial has been initiated to evaluate the efficacy and safety of Sativex® in the treatment of pain in patients with advanced cancer, who experience inadequate analgesia during optimized chronic opioid therapy.

The principal investigator of this study is Dr. Russell K. Portenoy, Chairman of the Department of Pain Medicine and Palliative Care at Beth Israel Medical Center in New York City. This five-week, placebo-controlled study will include approximately 40 centers primarily in the US and recruit a total of 336 patients. Patients enrolled in this study must have advanced cancer for which there is no known curative therapy and have a clinical diagnosis of cancer-related pain, which is not wholly alleviated with their current opioid treatment. The primary objective of the study is to evaluate the potential role and dose range of Sativex in these patients as an adjunct to their pre-existing pain medications. The primary endpoint of the study will be the response rate for patients at the end of 5 weeks of therapy, as defined by a 30% or greater reduction in the 11-point, Numeric Rating Scale (NRS).

Commenting on the importance of this study, Dr. Portenoy, said, “Studies suggest that more than one-third of patients with cancer, and more than three-quarters of those with advanced disease, have chronic pain. Large surveys indicate that optimal opioid therapy does not yield sufficient relief in a substantial proportion of these patients. There is a clear need for new treatments to improve these outcomes and it is our hope that cannabinoid formulations may represent an important option in the future. This US-based study is a welcome step in assessing the role of Sativex® as a potential new treatment for cancer pain."

Dr Geoffrey Guy, GW’s Chairman, said, “GW has spent many years preparing for the US development of Sativex® and has established open and positive interactions with relevant federal agencies. The start of the first large scale US clinical trial is a major milestone for the company and for the future prospects for Sativex®. We are delighted to be working in close collaboration with our partner, Otsuka, in advancing Sativex® toward the goal of obtaining US regulatory approval."

Dr. Taro Iwamoto, President of Otsuka Pharmaceutical Development and Commercialization, Inc., likewise noted that “Otsuka is very excited to be working with GW Pharmaceuticals for the development of this potential alternative approach to the treatment of advanced cancer pain. The initiation of this US clinical trial for Sativex is consistent with our mission to develop products for better health.”

Sativex® is an investigational new product composed primarily of two cannabinoids: CBD (cannabidiol,) and THC (delta 9 tetrahydrocannabinol). Sativex® will be administered as a metered dose oro-mucosal spray each 100µL spray contains 2.7mg THC and 2.5mg CBD. The Sativex® formulation is standardized by both composition and dose and is supplied in small spray vials. The components of Sativex have been shown to bind to cannabinoid receptors that are distributed throughout the central nervous system and in immune cells.

This Phase II/III dose ranging study will attempt to replicate and extend data from a previous, two-week clinical trial in 177 patients conducted in Europe. In this European study, Sativex® was administered to patients with terminal cancer and persistent pain that was not fully relieved by current strong opioid therapy. The primary endpoint of this study was the change from baseline to endpoint in the NRS pain score. Sativex, as adjunctive treatment to strong opioid therapy, was associated with a larger decrease in NRS score than was placebo and strong opiods (p=0.014). In addition, 43% of patients who received Sativex®, while remaining on opioids, exhibited at least a 30% decrease in their pain score compared to 21% of patients receiving placebo and opioids (p= 0.024)

Treatment related adverse events in this study were reported by 85% of patients receiving Sativex and by 75% of patients receiving placebo. The most common adverse events (> 10%) reported by patients in this study were somnolence (15% Sativex® vs. 13% placebo); nausea (12% Sativex® vs. 11% placebo) and dizziness (12% Sativex® vs. 5% placebo). Serious adverse events reported by more than one patient receiving Sativex were urinary retention (n=2) and progression of the underlying cancer (n=6).
Enquiries:

For GW:
GW Pharmaceuticals plc Today: +44 20 7831 3113
Dr Geoffrey Guy , Chairman Thereafter: + 44 1980 557000
Justin Gover, Managing Director
Mark Rogerson , Press and PR Tel: + 44 7885 638810

Financial Dynamics Tel: +44 20 7831 3113
David Yates, Ben Atwell

For Otsuka: US Inquiry
Debbie Kaufmann Tel: +1 240 683 3568
Japan Inquiry
Hideki Shirai siraih@otsuka.jp

Notes to Editors

About GW-Otsuka

On 14 February 2007, GW and Otsuka entered into a major long term strategic alliance. The relationship commenced with the signing of an exclusive license agreement to develop and market Sativex® GW’s lead product, in the US. Under this agreement, GW and Otsuka jointly oversee US clinical development and regulatory activities as well as the commercialization strategy. GW is responsible for carrying out the US clinical development program, the costs of which are borne by Otsuka. Otsuka will be responsible for the marketing and sales activities in the US.

On 9 July 2007, GW and Otsuka signed a global research collaboration for the study of cannabinoids in the field of Central Nervous System (CNS) and oncology to research, develop and commercialize a range of candidate cannabinoid products.

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.

The Otsuka Pharmaceutical Group comprises 99 companies and employs approximately 31,000 people in 17 countries and regions worldwide. Otsuka and its consolidated subsidiaries earned US$7.2 billion in annual revenues in fiscal 2006.

Focusing on the central nervous system, the circulatory, respiratory, and digestive systems, ophthalmology and dermatology, Otsuka’s pharmaceutical product business engages in the research and development, manufacture and sale of pharmaceuticals, aiming to maximize the assets of a global network to address unmet medical meets.
For additional information, visit www.otsuka-global.com

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 that alleviate pain and other neurological symptoms in patients who suffer from serious ailments. GW has assembled a team of over 100 scientists with extensive experience in developing 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.