GW was co-founded in 1998 by Dr Geoffrey Guy and Dr Brian Whittle, two well-known entrepreneurs in the UK biotech sector. In setting up GW, Dr Guy and Dr Whittle worked closely with both the UK Home Office and the UK’s medicines regulatory authority on establishing necessary licences and procedures so as to facilitate the progress of GW’s cannabinoid research programme. Dr Guy and Dr Whittle also worked with various branches of UK law enforcement to ensure the strictest security surrounds any work conducted involving the company’s cannabis plant material.




 Patients have been at the forefront of GW’s efforts since the Group was founded. Unusually, GW was set up specifically in response to a serious unmet medical need and has throughout its history received thousands of supportive letters from patients. Maintaining focus on the potential benefits to patients of its research has been a consistent driving force behind GW’s progress to date.

 Official Support

In 1998-99, there were two major official investigations into cannabinoid science and more broadly the issues related to the medical benefits of cannabis - by the House of Lords in the UK and the National Academy of Sciences, Institute of Medicine in the United States.i,ii,iii. Both of these investigations concluded that there is strong evidence supporting the potential therapeutic effects of components of the cannabis plant particularly in the field of Multiple Sclerosis and pain management, and recommended that clinical trials on appropriate medicinal formulations be performed as soon as possible. GW’s research was highlighted by the House of Lords as holding significant promise.




Listing on AIM

In 2001, GW’s shares began trading on AIM, a market of the London Stock Exchange, under the symbol “GWP”.


In just one year following its inception, GW commenced its first clinical trials evaluating different cannabinoid formulations as potential treatments in the fields of MS and pain. Rapidly, GW focused on the development of Sativex, an oral mucosal spray with two principal cannabinoid components, Cannabidiol (CBD) and Delta-9 Tetrahydrocannabinol (THC). Since 1999, the safety and efficacy of Sativex has been studied in over 20 randomised placebo-controlled trials including over 3,000 patients.
In 2003, GW entered into its first pharmaceutical licence agreement with Bayer for the UK marketing rights to Sativex. This agreement was expanded to include Canada later that year. In 2005, GW and Almirall signed a licence agreement granting Almirall exclusive marketing rights to Sativex in Europe (ex-UK). In 2007, GW granted Otsuka the US development and marketing rights to the product. In 2011, GW signed an agreement with Novartis to distribute Sativex in Australasia, Middle-East, Africa and Asia (excluding China and Japan). In 2014, GW signed an agreement with Ipsen to distribute Sativex in Latin America.



Sativex was first approved in Canada in 2005 under Health Canada’s Notice of Compliance with conditions (NOC/c) policy for the treatment of neuropathic pain in MS.
In 2010, Sativex was approved in the UK and Spain for the treatment of MS spasticity. The UK launch took place in June 2010. Following achievement of national reimbursement status in Spain in February 2011, Sativex was launched in that country in March 2011.

Since 2010, Sativex has been the subject of numerous additional regulatory submissions and approvals. A list of the countries in which Sativex is approved can be found here.

 In the United States, the lead indication for Sativex is cancer pain. Following positive data reported in March 2010 from a Phase 2b study, a Phase 3 clinical programme is now underway. We are also advancing plans to commence Phase 3 clinical development in the US for Sativex in the treatment of MS spasticity.

 New cannabinoid targets and research

In only the very recent past, a natural cannabinoid receptor system in the human body has been discovered. This has sparked renewed interest in the therapeutic potential of cannabinoids by identifying important new targets for drugs. In response to important new science and in parallel with the development of Sativex, GW has continued to explore the potential of a range of novel cannabinoid molecules in a number of distinct therapeutic areas. GW has set up relationships with leading cannabinoid scientists around the world.




In 2009, GW’s research in the field of type 2 diabetes and metabolic disease was expanded through an exclusive strategic alliance with Professor Mike Cawthorne and the Clore Laboratory, University of Buckingham. As part of this alliance, a dedicated section of the Clore Laboratory has been named the “GW Metabolic Research Laboratory”.
In early 2012, Professor Vincenzo Di Marzo agreed to direct GW’s global pre-clinical research programme and assumed the title of Research Director of GW Research Ltd and GW’s Cannabinoid Research Institute. Professor Di Marzo is one of the world’s leading cannabinoid scientists, co-author of more than 460 peer-reviewed publications, and in 2010 was recognised as Thompson Reuters 'top scientist of the decade' for pharmacology and toxicology. He has previously served as President of the International Cannabinoid Research Society (ICRS) and is a recipient of ICRS’s Mechoulam Award for “outstanding contributions to cannabinoid research”.

In addition to Sativex in MS and cancer pain,, specific therapeutic areas in which GW is currently conducting clinical trials for pipeline product candidates include epilepsy, type 2 diabetes, ulcerative colitis, glioma, and schizophrenia.

Nasdaq Listing

In May 2013, GW issued American Depositary Shares (ADSs) on the Nasdaq Global Market through an Initial Public Offering. In January 2014, GW successfully completed a $100 million follow-on offering of ADSs on Nasdaq.

Epidiolex® Orphan Drug Program

Following 6 years of pre-clinical studies of cannabinoids in the field of epilepsy, in 2013, GW commenced an orphan clinical program in pediatric epilepsy and was granted orphan drug designation by the FDA for its investigational medicine, Epidiolex.

GW has conducted extensive pre-clinical research of CBD in epilepsy and has reported significant anti-epileptiform and anticonvulsant activity using a variety of in vitro and in vivo models. This research has shown the ability of CBD to treat seizures in acute animal models of epilepsy with significantly fewer side effects than existing anti-epileptic drugs. GW’s epilepsy program strategy is to develop the scientific evidence, through placebo-controlled clinical trials, that lead to FDA-approved pharmaceutical products.

In 2014, GW received Orphan Drug Designation from the FDA for Epidiolex for the treatment of both Dravet syndrome and Lennox-Gastaut syndrome (LGS), each of which are severe infantile-onset, genetic, drug-resistant epilepsy syndromes. Additionally, GW has received Fast Track Designation from the FDA and Orphan Designation from the European Medicines Agency (EMA) for Epidiolex for the treatment of Dravet syndrome.

In October 2014, GW commenced a formal development program for Epidiolex, a liquid formulation of highly purified extract of Cannabidiol (CBD) as a treatment for severe, drug-resistant childhood epilepsy.

In parallel with the company’s formal clinical trial program, the FDA has granted 32 INDs to independent investigators in the United States to treat a total of approximately 400 children and young adults suffering from intractable epilepsy with Epidiolex. Twelve week treatment data on 58 patients as well as safety data from an additional 93 patients (for whom 12 week treatment effect data was not yet available) from these INDs have been made available to GW from the physicians conducting these studies.





i  House of Lords Select Committee on Science and Technology, 9th Report, “Cannabis – the Scientific and Medical Evidence”, 4th November 1998

ii  Therapeutic Uses of Cannabis. 2nd Report, Session 2000-2001

iii  Institute of Medicine, Division of Neuroscience and Behavioral Health, Janet E. Joy, Stanley J. Watson, Jr., and John A. Benson, Jr., “Marijuana and Medicine: Assessing the Science Base”

British Medical Association (1997) “Therapeutic Uses of Cannabis”, Morgan, D.R.  (editor), Ashton, C.H (principal author), Holdcroft, A., Mars, S., Moffat, T., Pertwee, R.G. and Wall, P. (contributing authors), Harwood Academic Publishers, Amsterdam.