-Three Phase 3 Epidiolex clinical trials fully recruited above target sample size – on track for initial data in March 2016-

 GW Pharmaceuticals plc (GWPH) (GWP.L) (AIM:GW) (the Company or the Group), a biopharmaceutical company focused on discovering, developing and commercializing novel therapeutics from its proprietary cannabinoid product platform, announces financial results for the first quarter ended 31 December 2015.

“We are on track to report topline data from four Epidiolex Phase 3 trials in the months ahead and remain very excited at the transformational potential of these data for GW. The treatment effect data from our expanded access program provide a solid basis for confidence in the outcome of these trials and the potential for Epidiolex to make a meaningful difference to the lives of patients with Dravet syndrome and Lennox-Gastaut syndrome,” stated Justin Gover, GW’s Chief Executive Officer. “We are looking forward to an active 2016, that, in addition to the Epidiolex Phase 3 data, is expected to include our first NDA filing, expansion of our U.S. commercial organization, and ongoing data read-outs from a number of clinical pipeline programs.”

RECENT OPERATIONAL HIGHLIGHTS

• Epidiolex^® (CBD) childhood epilepsy program:
  • Company sponsored Phase 3 development programs in Dravet syndrome and Lennox-Gastaut syndrome (LGS)
    • First Phase 3 Dravet syndrome trial fully enrolled above original target sample size (120 randomized), data expected March 2016
    • Second Phase 3 Dravet syndrome trial ongoing, data expected H2 2016
    • Both LGS Phase 3 trials fully enrolled above original target sample sizes (171 for 2-arm, 225 for 3-arm randomized), data expected Q2 2016
    • 97% transition rate of eligible patients from Phase 3 trials to long term open label extension
    • NDA submission with FDA expected Q4 2016
    • Phase 3 Tuberous Sclerosis Complex trial due to commence Q1 2016
    • Additional clinical development for Epidiolex expected to commence in H2 2016
  • Expanded access program
    • Recent data update at the American Epilepsy Society December 2015 Annual Meeting showing promising safety and effectiveness consistent with prior updates
    • Over 375 children and young adults on treatment at 22 U.S. clinical sites
    • Over 900 children and young adults authorized for treatment by FDA under Expanded Access Treatment INDs and 6 U.S. State programs
• Advanced clinical programs in multiple cannabinoid pipeline product candidates:
  • THCV Phase 2 study in type-2 diabetes data expected Q2 2016
  • THC:CBD Phase 1b/2a study for the treatment of Recurrent Glioblastoma Multiforme (GBM) fully enrolled with data expected in mid-2016
    • Orphan Drug Designation granted from FDA and EMA
  • Sativex^® Phase 2 study in spasticity due to cerebral palsy ongoing with data expected H2 2016
  • CBDV Phase 2 partial-onset epilepsy study in adults ongoing. Part A complete and Part B underway with data expected around the end of 2016
  • Neonatal Hypoxic-Ischemic Encephalopathy (NHIE) intravenous CBD Phase 1 clinical program expected to commence in H2 2016
    • Orphan Drug and Fast Track Designations granted from FDA and EMA
  • Clinical trials within the field of autism spectrum disorders expected to commence in H2 2016
• Pre-clinical progress addressing a number of areas of unmet need including autism spectrum disorders, Duchenne muscular dystrophy, glioma, ovarian and pancreatic cancers

FINANCIAL HIGHLIGHTS

• Revenue for the three months ended 31 December 2015 of £3.7 million ($5.4 million) compared to £8.0 million for the three months ended 31 December 2014
• Loss for the three months ended 31 December 2015 of £17.7 million ($26.2 million) compared to £3.4 million for the three months ended 31 December 2014
• Cash and cash equivalents at 31 December 2015 of £219.3 million ($324.1 million) compared to £234.9 million as at 30 September 2015

Conference Call and Webcast Information

GW Pharmaceuticals will host a conference call and webcast to discuss the first quarter 2016 financial results today at 8:00 a.m. EST / 1:00 p.m. GMT. To participate in the conference call, please dial 877-407-8133 (toll free from the U.S. and Canada), or 0800-756-3429 (toll free from the UK) or 201-689-8040 (international). Investors may also access a live audio webcast of the call via the investor relations section of the Company’s website at https://www.gwpharm.com. A replay of the call will also be available through the GW website shortly after the call and will remain available for 90 days. Replay Numbers: (toll free):1-877-660-6853, (international):1-201-612-7415. For both dial-in numbers please use conference ID # 13629628.

About GW Pharmaceuticals plc

Founded in 1998, GW is a biopharmaceutical company focused on discovering, developing and commercializing novel therapeutics from its proprietary cannabinoid product platform in a broad range of disease areas. GW commercialized the world’s first plant-derived cannabinoid prescription drug, Sativex®, which is approved for the treatment of spasticity due to multiple sclerosis in 28 countries outside the United States. GW is advancing an orphan drug program in the field of childhood epilepsy with a focus on Epidiolex® (cannabidiol), which is in Phase 3 clinical development for the treatment of Dravet syndrome and Lennox-Gastaut syndrome and which is also expected to enter Phase 3 clinical trials in the treatment of Tuberous Sclerosis Complex. GW has a deep pipeline of additional cannabinoid product candidates which includes compounds in Phase 1 and 2 trials for glioma, type 2 diabetes, schizophrenia and epilepsy. For further information, please visit www.gwpharm.com

Forward-looking statements

This news release contains forward-looking statements that reflect GW’s current expectations regarding future events, including statements regarding financial performance, the timing of clinical trials, the relevance of GW products commercially available and in development, the clinical benefits of Sativex® and Epidiolex® and the safety profile and commercial potential of Sativex and Epidiolex. 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 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, Epidiolex and other products by consumer and medical professionals. A further list and description of risks and uncertainties associated with an investment in GW can be found in GW’s filings with the U.S. Securities and Exchange Commission. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. GW undertakes no obligation to update or revise the information contained in this press release, whether as a result of new information, future events or circumstances or otherwise.

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GW Pharmaceuticals plc
Condensed consolidated income statement
Three months ended 31 December 2015 and 2014

All activities relate to continuing operations.

Condensed consolidated statement of comprehensive loss
For the three months ended 31 December 2015 and 2014

GW Pharmaceuticals plc
Condensed consolidated statement of changes in equity
Three months ended 31 December 2015 and 2014

GW Pharmaceuticals plc
Condensed consolidated balance sheets
As at 31 December 2015 and 30 September 2015

GW Pharmaceuticals plc
Condensed consolidated cash flow statements
For the three months ended 31 December 2015 and 2014