X0306 4 2020-11-13 0 0001351288 GW PHARMACEUTICALS PLC GWPH 0001754129 Gover Justin D. SOVEREIGN HOUSE, VISION PARK, HISTON CAMBRIDGE X0 CB24 9BZ UNITED KINGDOM 1 1 0 0 Chief Executive Officer Ordinary Shares 2020-11-13 4 M 0 39060 0.0013 A 495113 D Ordinary Shares 2020-11-13 4 M 0 3924 0.0013 A 499037 D Ordinary Shares 2020-11-13 4 S 0 42984 10.01 D 456053 D Ordinary Shares 2020-11-16 4 M 0 22800 0.0013 A 478853 D Ordinary Shares 2020-11-16 4 S 0 22800 10.02 D 456053 D Ordinary Shares 2020-11-17 4 M 0 42708 0.0013 A 498761 D Ordinary Shares 2020-11-17 4 S 0 42708 10.03 D 456053 D Stock Options 0.0013 2020-11-13 4 M 0 39060 0.00 D 2020-01-06 2021-03-15 Ordinary Shares 39060 166917 D Stock Options 0.0013 2020-11-13 4 M 0 3924 0.00 D 2020-02-15 2021-03-15 Ordinary Shares 3924 10 D Stock Options 0.0013 2020-11-16 4 M 0 22800 0.00 D 2020-01-06 2021-03-15 Ordinary Shares 22800 144117 D Stock Options 0.0013 2020-11-17 4 M 0 42708 0.00 D 2020-01-06 2021-03-15 Ordinary Shares 42708 101409 D Exercise of stock options. Following the exercise, these shares were converted into American Depositary Shares ("ADS") of the Issuer. Each ADS represents twelve ordinary shares of the Issuer. Converted from British Pounds Sterling to U.S. Dollars using currency ratio of 1.00 British Pound Sterling = 1.32 U.S. Dollars as of November 13, 2020. The sales reported were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 12, 2020. Represented by ADSs. Converted from price per ADS. The price reported in Column 4 is a weighted average price per ordinary share ($120.1533 per ADS). These shares were sold in multiple transactions at prices ranging from $120.00 per ADS (or $10.00 per ordinary share) to $120.99 per ADS (or $10.08 per ordinary share), inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. Converted from British Pounds Sterling to U.S. Dollars using currency ratio of 1.00 British Pound Sterling = 1.32 U.S. Dollars as of November 16, 2020. The price reported in Column 4 is a weighted average price per ordinary share ($120.2065 per ADS). These shares were sold in multiple transactions at prices ranging from $120.00 per ADS (or $10.00 per ordinary share) to $120.49 per ADS (or $10.04 per ordinary share), inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. The price reported in Column 4 is a weighted average price per ordinary share ($120.3923 per ADS). These shares were sold in multiple transactions at prices ranging from $120.00 per ADS (or $10.00 per ordinary share) to $120.85 per ADS (or $10.07 per ordinary share), inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. Converted from British Pounds Sterling to U.S. Dollars using currency ratio of 1.00 British Pound Sterling = 1.33 U.S. Dollars as of November 17, 2020. /s/ Justin D. Gover 2020-11-17