Closing of U.S. Public Offering Raising $289.8m

GW Pharmaceuticals plc Announces the Closing of U.S. Public Offering of American Depositary Shares (ADSs) Raising $289.8 Million on the NASDAQ Global Market and Full Exercise of Underwriter's Option to Purchase Additional ADSs

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LONDON, UK, 18 July 2016: GW Pharmaceuticals plc (Nasdaq: GWPH, AIM: GWP, "GW" or the "Company"), a biopharmaceutical company focused on discovering, developing and commercializing novel therapeutics from its proprietary cannabinoid product platform, announced today the closing of the previously announced offering on the NASDAQ Global Market by GW of 2,800,000 of American Depositary Shares (ADSs) and the full exercise by the underwriters of their option to purchase 420,000 additional ADSs from GW at a price of $90.00 per ADS, raising gross proceeds of $289,800,000 (before deducting underwriting discounts, commissions and offering expenses).

Morgan Stanley, BofA Merrill Lynch and Goldman, Sachs & Co. are acting as joint book-running managers for the offering. Cowen and Company is acting as lead manager and Piper Jaffray is acting as manager.

The ADSs described above were offered by GW pursuant to a shelf registration statement filed by GW with the Securities and Exchange Commission ("SEC") that became automatically effective on May 7, 2014. The offering of the ADSs was made only by means of a prospectus and prospectus supplement. You may obtain these documents on the SEC's website at http://www.sec.gov. Alternatively, the prospectus and prospectus supplement may be obtained from Morgan Stanley & Co. LLC, Attention: Prospectus Department, 180 Varick Street, 2nd Floor, New York, New York 10014; BofA Merrill Lynch, NC1-004-03-43, 200 North College Street, 3rd Floor, Charlotte, NC 28255-0001, Attention: Prospectus Department, email: [email protected]; or from Goldman, Sachs & Co., Attention: Prospectus Department, 200 West Street, New York, NY 10282, telephone: 1-866-471-2526, facsimile: 212-902-9316 or by emailing [email protected].

The 38,640,000 new ordinary shares being issued by the Company pursuant to the offering (the "New Shares") will, when issued, be credited as fully paid and will rank pari passu in all respects with the existing ordinary shares of the Company, including the right to receive all dividends and other distributions declared, made or paid in respect of such shares after the date of issue of the New Shares.

Application has been made to the London Stock Exchange for the New Shares to be admitted to the AIM market operated by the London Stock Exchange. It is expected that admission will become effective at 8:00 a.m. on July 19, 2016.

This press release does not constitute a prospectus and does not constitute or form, and will not form, part of any offer or invitation to sell or issue, or the solicitation of an offer to purchase or acquire, any of the ordinary shares or ADSs or any other securities in the United States of America or in any other jurisdiction. Securities may not be offered or sold in the United States of America absent registration or an exemption from registration under the United States Securities Act of 1933, as amended (the "Securities Act"). Any public offering of securities to be made in the United States will be made by means of a prospectus. Such prospectus will contain detailed information about the issuer and its management and financial statements. This press release is being issued pursuant to and in accordance with Rule 135e under the Securities Act.

No money, securities or other consideration is being solicited, and, if sent in response to the information contained in this press release, will not be accepted.

Members of the public outside the United States will not be eligible to take part in the offering described above.

This press release is not directed to, or intended for distribution or use by, any person or entity that is a citizen or resident or located in any locality, state, country or other jurisdiction where such distribution, publication, availability or use would be contrary to law or regulation or which would require any registration or licensing within such jurisdiction.

The distribution of this press release into jurisdictions other than the UK may be restricted by law. Persons into whose possession this announcement comes should inform themselves about and observe any such restrictions.

For readers in the European Economic Area

In any EEA Member State that has implemented the Prospectus Directive, this communication is only addressed to and directed at qualified investors in that Member State within the meaning of the Prospectus Directive. The term "Prospectus Directive" means Directive 2003/71/EC (and amendments thereto, including Directive 2010/73/EU, to the extent implemented in each relevant Member State), together with any relevant implementing measure in the relevant Member State.

For readers in the United Kingdom

This communication, in so far as it constitutes an invitation or inducement to enter into investment activity (within the meaning of s21 Financial Services and Markets Act 2000 as amended) in connection with the securities which are the subject of the offering described in this press release or otherwise, is being directed only at (i) persons who are outside the United Kingdom or (ii) persons who have professional experience in matters relating to investments who fall within Article 19(5) ("Investment professionals") of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (the "Order") or (iii) certain high value persons and entities who fall within Article 49(2)(a) to (d) ("High net worth companies, unincorporated associations etc") of the Order; or (iv) any other person to whom it may lawfully be communicated (all such persons in (i) to (iv) together being referred to as "relevant persons"). The ADSs are only available to, and any invitation, offer or agreement to subscribe, purchase or otherwise acquire such ADSs will be engaged in only with, relevant persons. Any person who is not a relevant person should not act or rely on this document or any of its contents.

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 is advancing an orphan drug program in the field of childhood-onset epilepsy with a focus on Epidiolex® (cannabidiol), which is in Phase 3 clinical development for the treatment of Dravet syndrome, LGS and Tuberous Sclerosis Complex. GW successfully 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 has a deep pipeline of additional cannabinoid product candidates which includes compounds in Phase 1 and 2 trials for glioma, schizophrenia and epilepsy.

Forward-looking statements

This news release may contain forward-looking statements that reflect GWs current expectations regarding future events, including statements regarding the therapeutic benefit, safety profile and commercial value of the Company's investigational drug Epidiolex, the development and commercialization of Epidiolex, plans and objectives for product development, plans and objectives for present and future clinical trials and results of such trials, plans and objectives for regulatory submissions and approvals. 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, Epidiolex, if approved, and other products which we may commercialize by consumers and medical professionals. A further list and description of risks, uncertainties and other risks 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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