Research Update

RNS Number:9279I
GW Pharmaceuticals PLC
03 December 2007




       GW Commences Sativex(R) Phase III Clinical Trial in MS Spasticity

          Trial Designed to Secure European Regulatory Approval in 
                           MS Spasticity Indication


Porton Down, UK; 3 December 2007: GW Pharmaceuticals plc (AIM: GWP) today
announces that it has started a new Phase III trial of Sativex(R) in Multiple
Sclerosis (MS) Spasticity. This trial is designed to resolve the outstanding
issue arising from the recent European regulatory submission and to provide the
basis for regulatory approval of Sativex in the indication of MS Spasticity. The
study aims to report headline results towards the end of 2008.

The protocol design of this study follows clear guidance provided by the
regulators in both their recent regulatory assessment and additional scientific
advice meetings.

The objective of the study is to satisfy the regulator's outstanding requirement
for clarification related to the magnitude of the treatment effect of Sativex in
"responders" (those patients that respond to treatment). In previous MS
Spasticity clinical trials, the benefit obtained by responders has to some
extent been masked by looking at the mean improvement across the whole studied
patient population, which comprises both responders and non-responders.

GW's existing clinical data in MS Spasticity, analysed on a "post-hoc" basis,
has shown that responders can be reliably identified after four weeks treatment
and that, after 12 weeks, the difference from placebo is clinically important
and highly statistically significant (p=0.015). The regulators have required
that this analysis be replicated in a prospectively planned study.

The new study therefore follows an "enriched design" which first identifies
responders over a four week period (Phase A), and then focuses on analysing the
effect of Sativex vs placebo on those responders over a further period of 12
weeks (Phase B). The study aims to recruit a total of 244 patients into Phase B.
The primary endpoint of the study is the difference between the Sativex and
placebo groups in Phase B of the study in MS Spasticity as measured on a Numeric
Rating Scale. This study will include hospital centres across five European
countries.

Dr Stephen Wright, R&D Director, said, "This new study is an explicit
requirement of the regulatory authorities and provides a route to approval for
Sativex in the relief of MS-related spasticity. This study is designed to
provide compelling evidence of clinically relevant benefit for Sativex in this
population of people with MS and we look forward to reporting results towards
the end of 2008."


Sativex Resubmission

There are now two potential short term opportunities to re-submit Sativex for
regulatory approval in Europe. In the indication of MS Neuropathic Pain, a
second pivotal Phase III trial has already completed patient recruitment and is
due to report headline results in the first quarter of 2008. This could lead to
a regulatory filing in this indication in the first half of 2008. In the event
that GW does not submit the MS Neuropathic Pain indication, the second
opportunity is to resubmit for MS Spasticity following completion of the new
study which has commenced today.

In addition to the MS indications, future European regulatory submissions are
planned for Sativex in cancer pain and in peripheral neuropathic pain. The
cancer pain clinical development programme is being conducted in the United
States and funded under the collaboration with Otsuka Pharmaceutical Co. Ltd.


Enquiries:

GW Pharmaceuticals plc                                   Today: [phone]
Dr Geoffrey Guy, Chairman                           Thereafter: + 44 1980 557000
Justin Gover, Managing Director
Mark Rogerson, Press and PR                                Tel: + 44 7885 638810

Financial Dynamics                                         Tel: [phone]
David Yates, Ben Atwell



Notes to Editors

About Sativex

Sativex is composed primarily of two cannabinoids: CBD (cannabidiol) and THC
(delta 9 tetrahydrocannabinol). Sativex is administered as a metered dose
oro-mucosal spray; each 100uL 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.

Sativex is already approved and marketed in Canada as adjunctive treatment for
the symptomatic relief of neuropathic pain in MS, and for the relief of cancer
pain.  Health Canada has approved Sativex under its Notice of Compliance with
conditions (NOC/c) policy.

In the US, the lead indication for Sativex is cancer pain. On 26 November, GW
and its US licensing partner, Otsuka, announced that the first US Phase II/III
cancer pain trial had been initiated.

GW has to date entered into three Sativex license agreements - with Otsuka in
the US, with Bayer HealthCare in the UK and Canada, and with Almirall in Europe
(ex-UK).


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(R) and other products by
consumer and medical professionals.






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