As previously disclosed, on February 3, 2021, GW Pharmaceuticals plc, a public limited company incorporated under the laws of England and Wales
(GW), entered into a transaction agreement (the Transaction Agreement) with Jazz Pharmaceuticals Public Limited Company, an Irish public limited company (Jazz), and Jazz Pharmaceuticals UK
Holdings Limited, a private limited company incorporated under the laws of England and Wales and a wholly owned subsidiary of Jazz (Bidco), pursuant to which, on the terms and subject to the conditions set forth therein, Bidco
will acquire the entire issued and to be issued share capital of GW pursuant to a scheme of arrangement under Part 26 of the United Kingdom Companies Act 2006 (such acquisition, the Transaction). On March 15, 2021, GW
filed a definitive proxy statement with the Securities and Exchange Commission in connection with the Transaction (the Proxy Statement).
Since the initial filing of the Proxy Statement, twelve complaints have been filed in federal courts in California, New York and Pennsylvania and a state
court in New York by purported GW shareholders against GW and the members of the GW board of directors in connection with the Transaction: Farrell v. GW Pharmaceuticals plc, et al., Case No. 1:21-cv-02344 (filed March 17, 2021) (S.D.N.Y.), Hinton v. GW Pharmaceuticals plc, et al., Case No. 1:21-cv-02379
(filed March 18, 2021) (S.D.N.Y.), Brady v. GW Pharmaceuticals plc, et al., Case No. 1:21-cv-02382 (filed March 18, 2021) (S.D.N.Y.), Warren v. GW
Pharmaceuticals plc, et al., Case No. 1:21-cv-02536 (filed March 24, 2021) (S.D.N.Y.), Goodman v. GW Pharmaceuticals plc, et al., Case No. 1:21-cv-01574 (filed March 25, 2021) (E.D.N.Y.), Kent v. GW Pharmaceuticals, plc, et al., Case No.
3:21-cv-00530-MMA-AHG (filed March 26, 2021) (S.D. Cal.), Coffman v. GW
Pharmaceuticals plc, et al., Case No. 3:21-cv-00537-BEN-RBB (filed March 26,
2021) (S.D. Ca.), Shubitowski v. GW Pharmaceuticals plc, et al., Case No. 1:21-cv-02668 (filed March 29, 2021) (S.D.N.Y.), Hurlbut v. GW Pharmaceuticals
plc, et al., Case No. 2:21-cv-01500 (filed March 30, 2021) (E.D. Pa.), Olesky v. GW Pharmaceuticals, plc, et al., Case No.
1:21-cv-02741 (filed March 31, 2021) (S.D.N.Y) Ochoa v. GW Pharmaceuticals plc, et al., (3:21-cv-00580-BAS-BLM) (filed April 2, 2021) (S.D. Ca.) (collectively, the Federal Shareholder Litigation); and Levy v. Guy, et
al., Case No. 603237/2021 (filed March 17, 2021) (N.Y. Sup. Ct. Nassau Cty.) (the State Court Litigation and, collectively with the Federal Shareholder Litigation, the Transaction Litigation). Each
of the complaints in the Federal Shareholder Litigation includes allegations that, among other things, the Proxy Statement omitted certain material information in connection with the Transaction in violation of Sections 14(a) and 20(a) of the
Securities Exchange Act of 1934, as amended (the Exchange Act), and Rule 14a-9 promulgated under the Exchange Act, and one of those complaints also purports to allege claims that the members
of the GW board of directors breached fiduciary duties in connection with the Transaction. The State Court Litigation purports to allege misrepresentation claims under New York common law relating to the Proxy Statement. The plaintiffs in the
Transaction Litigation seek various remedies, including injunctive relief to prevent the consummation of the Transaction unless certain allegedly material information is disclosed or, in the alternative, rescission or damages and an award of
attorneys fees and expenses.
GW believes that the claims asserted in the Transaction Litigation are without merit and no additional disclosures are
required under applicable law. However, in order to avoid the risk of the Transaction Litigation delaying or adversely affecting the Transaction and to minimize the costs, risks and uncertainties inherent in litigation, and without admitting any
liability or wrongdoing, GW has determined to voluntarily make the following supplemental disclosures to the Proxy Statement, as described in this Current Report on Form 8-K. Nothing in this Current Report on
Form 8-K shall be deemed an admission of the legal necessity or materiality under applicable laws of any of the disclosures set forth herein. To the contrary, GW specifically denies all allegations in the
Transaction Litigation that any additional disclosure was or is required.
These supplemental disclosures will not affect the transaction deliverables to
be paid to shareholders of GW in connection with the Transaction or the timing of the Court Meeting and the General Meeting of the shareholders of GW scheduled for April 23, 2021, at 2:00 p.m. (London time) and 2:15 p.m. (London time),
respectively, at Kingsgate House, Newbury Road, Andover SP10 4DU, United Kingdom. The GW board of directors continues to unanimously recommend that you vote FOR the resolutions to be proposed at the Court Meeting and the General
Meeting described in the Proxy Statement.