Sativex Regulatory Update

SATIVEX® REGULATORY UPDATE

UK AND SPANISH REGULATORS CONFIRM NO MAJOR ISSUES OUTSTANDING

Regulatory Process Now at Advanced Stage. Approvals Expected Q2 2010

Porton Down, UK, 18 March 2010: GW Pharmaceuticals plc (GWP:AIM) today provides an update on the progress of its regulatory submission for Sativex® Oromucosal Spray for the treatment of the symptoms of spasticity due to Multiple Sclerosis. The regulatory submission was filed in the UK and Spain under the European decentralised procedure in May 2009, with the UK acting as the Reference Member State.

The regulatory process has now reached "Day 150" of the decentralised procedure and both the UK and Spanish regulators have concluded that there are no major quality, safety or efficacy issues remaining to be resolved. Resolution is now required only of points of clarification related to finalisation of wording on the patient information leaflet. We expect this document to be reviewed by the regulators in the coming weeks.

Once the regulators have agreed final wording on the patient leaflet, the decentralised procedure can close and the process will enter its final phase. This final phase, known as the national phase, takes place separately in the UK and Spain and its purpose is to finalise local wording on product packaging and related documents.

GW therefore expects regulatory approval in the UK and Spain during Q2 2010.

Dr Stephen Wright, GW's R&D Director, said, "This is a major milestone in the regulatory process for Sativex, and for GW's future prospects. We look forward to working with the regulators towards a successful completion of this process and to supporting our marketing partners as they prepare for product launch. This progress with Sativex also provides further validation of GW's cannabinoid platform and the significant long term promise of GW's portfolio of cannabinoid medicines."

Sativex will be marketed in the UK by Bayer Schering Pharma, and in the rest of the European Union by Almirall S.A. Upon UK regulatory approval, GW expects to receive a £10m milestone payment from Bayer. A further £2.5m milestone payment is payable by Almirall following both regulatory and pricing approval in Spain. 

Following approval in the UK and Spain, submissions for approval will made in additional European countries during 2010 under the mutual recognition procedure.

There will be a conference call for analysts today at 10.00am. Analysts should contact Juliet Edwards at Financial Dynamics on +44 (0) 20 7831 3113 for details. There will be a live audio webcast of this call, which will be accessible on the presentations/webcasts page in the investor relations section of the GW website (www.gwpharm.com). A recording of this call will be available on the GW website later today.

Enquiries:

Notes to Editors

Regulatory Process

In the decentralized procedure, issues raised by the regulatory authorities are classified in terms of their importance. At Day 150 of the procedure, unresolved "major" issues mean that the product is not approvable. If all major issues are considered resolved at Day 150, the regulators deem the product to be approvable subject to resolution of any "points for clarification". Such points are necessary to resolve prior to approval but are not considered as barriers to approvability.

MS Spasticity

There are approximately 670,000 people with MS in Europe (source: European MS Platform).Spasticity (spasms and stiffness) is one of the most common symptoms of MS occurring in as many as three quarters of people with MS. Spasticity can affect many aspects of daily life, such as walking and sitting. Sativex aims to treat high need patients who have previously failed to gain adequate benefit from currently available anti-spasticity treatments.

About Almirall

Almirall is an international pharmaceutical company based on innovation and committed to health. Headquartered in Barcelona, Spain, it researches, develops, manufactures and commercialises its own R&D and licensed drugs with the aim of improving people's health and wellbeing. The therapeutic areas on which Almirall focuses its research resources are related to the treatment of asthma, COPD (Chronic Obstructive Pulmonary Disease), rheumatoid arthritis, multiple sclerosis, psoriasis and other dermatological conditions. Almirall's products are currently present in over 70 countries while it has direct presence in Europe and Latin America through 11 affiliates.

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.

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.