Letter of Appointment by and between GW Pharmaceuticals plc and Lord William Waldegrave, dated December 20, 2017

Your appointment as a non-executive Director of GW is subject to the Articles of Association of GW. You are required to retire and seek reelection by our shareholders at the next AGM, which is on 14 March 2018, and at any subsequent AGM as required by the Articles of Association or as the Board resolves. The Articles of Association require one third of the Directors to retire by rotation and seek re-election at each AGM, with each director being subject to re-election at intervals of not more than three years. Your appointment as a non-executive Director will automatically terminate without any entitlement to compensation if you:

are removed from office by a resolution of the shareholders;

are not re-elected to office; or

cease to be a director by reason of your vacating office pursuant to any provision of the Company’s Articles of Association.

730616627.1

1

The Company may terminate your appointment with immediate effect if you:

commit any act, whether or not in the course of your duties for the Company, which tends to bring you or the Company or Group into disrepute;

commit a material breach of your obligations under this letter;

commit any serious or repeated breach or non-observance of your obligations to the Company (which include an obligation not to breach your duties to the Company, whether statutory, fiduciary or common law);

are declared bankrupt or have made an arrangement with, or for the benefit of, your creditors;

are convicted of any arrestable criminal offence (other than an offence under road traffic legislation in the UK or elsewhere for which a fine or non-custodial penalty is imposed);

are disqualified from acting as a director; or

are unavailable to perform your duties under your appointment for 6 months consecutively or in aggregate in any period of one year.

During any period of notice in accordance with this agreement, the Company may at its absolute discretion ask you not to attend any Board or General meetings or to perform any other services on its behalf.

Non-executive directors on the GW Board are typically expected to serve two three-year terms but you may be invited by the Company to serve for an additional period on the Board. Any term renewal after your first three-year term is subject to Board review and re-election at the subsequent AGM. Notwithstanding any mutual expectation, there is no right to renomination by the Board, either annually or after any three-year period.

Upon the ending of your appointment for any reason, you will resign at the request of the Company, without any claim for compensation (other than for accrued and unpaid fees due under this letter), from all directorships and other offices held by you in the Company and any other member of the Group and from all trusteeships held by you of any pension scheme or other trusts established by any member of the Group. Should you fail to do so, you irrevocably appoint any member of the Board as your attorney in your name and on your behalf to sign any documents and take such other steps as are necessary to give effect to those resignations.

If matters arise which cause you concern about your role, you should discuss these matters with the Chairman of the Company. If you have any concerns which cannot be resolved, and you choose to resign for that, or any other, reason, you should provide an appropriate written statement to the Chairman of the Company for circulation to the Board.

730616627.1

2

You will be expected to devote such time as is necessary for the proper performance of your duties. You are expected to attend GW Board Meetings and General Meetings of the shareholders of GW as and when they are held. In connection with attendance at the meetings, you will exercise such functions that are specifically delegated to you from time to time by the Board.

You will also likely be required to sit on at least one sub sub-committee of the Board.

We expect this role to involve attendance at least five GW Board meetings, the GW Annual General Meeting (usually held on the same day as a Board meeting) and, Audit Committee meetings (typically scheduled to occur on Board meeting dates). Unless urgent and unavoidable circumstances prevent you from doing so, it is expected that you will attend these meetings, most of which will be held in the UK. One Board meeting per year is likely to be in the U.S.

Additional time may be required, on an ad-hoc basis, to attend meetings to deal with certain GW Board and sub-committee matters as they arise. The nature of the role makes it impossible to be specific about the maximum time commitment, and there is always the possibility of additional time commitment in respect of preparation time and ad hoc matters which may arise from time to time, and particularly when the Company is undergoing a period of increased activity. At certain times, it may be necessary to convene additional GW Board, committee or shareholder meetings.

In accepting this role you confirm that you have sufficient time available to commit to the proper performance of this role. Prior to acceptance of the role you will be required to provide to the Company Secretary details of your other Board appointments and significant commitments with a broad indication of the time involved and will be required to update the Company Secretary from time to time of any changes to these commitments.

You shall be paid an annual fee of £45,000 gross (current at the date of this letter). This fee covers all duties, excluding service on any subcommittee of the Board. If you are required to sit on a sub-committee committee, you will be paid an additional annual fee. This fee will vary depending upon the sub-committee on which you sit, as follows:

730616627.1

3

Your fees will be reviewed from time to time by the GW Board. It is our current practice to review these fees at the end of each calendar year although such review does not imply nor guarantee any increase.

You will not be entitled to participate in any Group pension scheme or to receive any other benefits offered by the Company.

You will be eligible to participate in the GW Pharmaceuticals Long Term Incentive Plan. Grants of equity based incentives under the terms of this scheme are made at the discretion of the Board, usually on an annual basis.

You will be reimbursed for all reasonable out-of-pocket expenses properly incurred by you on Company business, including costs associated with you attending UK Board, Committee and General Meetings so long as those costs are in accordance with the GW travel policy (a copy of which will be provided to you on request). Reimbursement would include the reasonable cost of obtaining legal advice, if circumstances should arise where it was necessary for you to seek such advice separately, about your responsibilities as a non-executive director of the Company although you should initially raise any such concerns with the Chairman of the Company. This advice should be obtained, and reimbursement will only be made, in accordance with any formal procedure for directors to take independent professional advice adopted from time to time by the Company and a copy of the current version will be supplied to you. Claims for reimbursement should be accompanied by evidence of expenditure.

730616627.1

4

You will be expected to perform your duties, whether statutory, fiduciary or common-law, faithfully, efficiently and diligently to a standard commensurate with both the functions of your role and your knowledge, skills and experience.

You will exercise your powers in your role as a non-executive director having regard to relevant obligations under prevailing law and regulation, including the Companies Act 2006. You are also required to comply with the requirements of Nasdaq. You will be advised by the Company Secretary where these differ from requirements in the UK.

You will have particular regard to the general duties of directors as set out in Part 10, Chapter 2 of the Companies Act 2006, including the duty to promote the success of the company:

the likely consequences of any decision in the long term,

the interests of the company’s employees,

the need to foster the company’s business relationships with suppliers, customers and others,

the impact of the company’s operations on the community and the environment,

the desirability of the company maintaining a reputation for high standards of business conduct, and

the need to act fairly as between members of the company.”

In your role as non-executive director you will be required to:

constructively challenge and help develop proposals on strategy;

scrutinise the performance of management in meeting agreed goals and objectives and monitor the reporting of performance;

satisfy yourself on the integrity of financial information and that financial controls and systems of risk management are robust and defensible;

determine appropriate levels of remuneration of executive directors and have a prime role in appointing and, where necessary, removing executive directors, and in succession planning;

devote time to developing and refreshing your knowledge and skills;

730616627.1

5

uphold high standards of integrity and probity and support me and the other directors in instilling the appropriate culture, values and behaviours in the boardroom and beyond;

insist on receiving high-quality information sufficiently in advance of board meetings; and

take into account the views of shareholders and other stakeholders where appropriate.

You will be required to exercise relevant powers under, and abide by, GW’s Articles of Association.

You will be required to exercise your powers as a director in accordance with GW’s policies and procedures.

You will disclose any direct or indirect interest which you may have in any matter being considered at a board meeting or committee meeting and, save as permitted under the Articles of Association, you will not vote on any resolution of the Board, or of one of its committees, on any matter where you have any direct or indirect interest.

You will immediately report to the Chairman your own wrongdoing or the wrongdoing or proposed wrongdoing of any employee or director of which you become aware.

Unless specifically authorised to do so by the Board, you will not enter into any legal or other commitment or contract on behalf of the Company.

730616627.1

6

corporate and marketing strategy, acquisition and investment proposals, business development and plans, maturing business opportunities, sales reports and research results;

business contacts, lists of customers and suppliers and details of contracts with customers and suppliers and their current or future requirements;

budgets, financial plans and management accounts, trading statements and other financial reports and information;

unpublished price sensitive information about the Group; and

any document marked “confidential” and any information which by its nature is commercially sensitive.

You are expected to comply with the Company’s Articles of Association, the City Code on Takeovers and Mergers, applicable stock exchange rules and regulations and the Company’s relevant internal codes and policies. In particular during your appointment you will comply, and will procure, so far as you are able, that your spouse or Civil Partner and dependent children (if any) or any trust in which you or your spouse or Civil Partner may be concerned or interested as trustee or beneficiary, comply with any code of conduct relating to securities transactions by directors and specified employees adopted by the Company from time to time.

You will promptly give the Company such information as the Company or any member of the Group may require to enable it to comply with its legal and regulatory obligations whether to any securities or investment exchange or regulatory or governmental body to which any member of the Group is, from time to time, subject or howsoever arising.

You will promptly give the Company such information, records and support as the Company or any member of the Group may require to enable it to prepare for, or respond to, any proceedings, inquiries or investigations into its activities by a regulatory or governmental authority. This requirement will survive termination or expiration of your appointment.

730616627.1

7

information about your physical or mental health or condition in order to monitor sick leave and take decisions as to your fitness to perform your duties;

information about you that may be relevant to ensuring equality of opportunity and treatment in line with the Company’s equal opportunities policy and in compliance with equal opportunities legislation; and

information relating to any criminal proceedings in which you have been involved, for insurance purposes and in order to comply with legal requirements and obligations to third parties.

730616627.1

8

For the purpose of this letter:

This letter will be construed in accordance with English law and you and the Company irrevocably submit to the exclusive jurisdiction of the English Courts to settle any dispute which may arise in connection with this letter.

This letter constitutes the entire terms and conditions of your appointment. No variation or addition to this letter and no waiver of any provision of it will be valid unless in writing and signed by or on behalf of both parties.

730616627.1

9