COMPASS Pathways : Notice of 2023 AGM

COMPASS PATHWAYS PLC

(the "Company")

3rd Floor 1 Ashley Road, Altrincham

Cheshire WA14 2DT

United Kingdom

(Incorporated and registered in England and Wales under the Companies Act 2006 with registered

number 12696098)

THIS DOCUMENT IS IMPORTANT AND REQUIRES YOUR IMMEDIATE ATTENTION.

If you are in any doubt as to the action to be taken, please seek your own financial advice from your stockbroker, solicitor, accountant or other appropriately authorised independent financial adviser.

If you have recently sold or transferred all of your shares in the Company, you should hand this document and all accompanying documents, as soon as possible, to the purchaser or transferee of those shares, or to the stockbroker, bank or other agent through whom the sale or transfer was effected for transmission to the purchaser or transferee.

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25 April 2023

Dear Shareholder

2023 Annual General Meeting of COMPASS Pathways plc (the "AGM" or "Meeting")

We are pleased to provide details of the AGM of COMPASS Pathways plc (the "Company") to be held as a physical meeting at 1:30 p.m. London time (8:30 a.m. Eastern Time) on Friday 2nd June 2023 at Goodwin Procter (UK) LLP, 100 Cheapside, London. The formal notice of AGM set out in this document (the "Notice of AGM") at pages 15 to 18 contains the shareholder resolutions to be proposed and voted on at the AGM.

Shareholder engagement

We appreciate that the AGM is your opportunity to receive an update on the Company and ask questions of the board of directors (the "Board"). To support engagement with our shareholders it is our intention to live stream the meeting by webcast and to enable questions relating to the AGM resolutions to be submitted in advance of the meeting.

The webcasting arrangements will allow shareholders to hear from the Company and follow the business of the AGM on their computer, tablet or smart phone from their location of choice, although this will not constitute formal attendance at the meeting and will not enable you to cast votes at the meeting. You will be able to access the AGM using the following online platform:

(https://onlinexperiences.com/Launch/QReg/ShowUUID=0872D0B8-C2A7-4F5B-8382-73237C4921D2)

Shareholder questions

Shareholders are invited to submit their questions in advance by sending an email to [e-mail] by 1:30 p.m. London time (8:30 a.m. Eastern Time) on Tuesday 30th May 2023.

We would like to respond to as many shareholders' questions as possible and therefore we will answer questions during the Meeting in a way that aims to best recognise the interests of all shareholders. To assist with this, we ask that you help us to facilitate access from as many shareholders as possible by limiting the number of questions and keeping your questions succinct, focused on and relevant to the business of the Meeting. In the interests of transparency for all shareholders, responses to questions not able to be addressed during the Meeting will be available on our website as soon as practicable following the Meeting.

Voting

We are holding our AGM as a physical meeting and are therefore unable to offer shareholders online voting facilities during the AGM. It is important that shareholders do still cast their votes in respect

of the business of the AGM. We encourage all shareholders to complete and return a proxy form appointing the Chairman of the meeting, as proxy. Further information on how to appoint a proxy is detailed on pages 11 to 12 of this Notice of AGM. In order to allow the voting preferences of all shareholders to be taken into account, a poll will be conducted on all resolutions proposed in this Notice of AGM. The results of the voting will be posted on the Company's website as soon as practicable after the meeting.

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Action to be taken

Ordinary Shareholders

If you are a holder of ordinary shares in the Company, please vote on the resolutions by appointing a proxy in accordance with the instructions set out at pages 11 to 12 of this Notice of AGM. A form of proxy for use by ordinary shareholders at the AGM is enclosed.

You are encouraged to appoint the Chairman of the AGM as your proxy.

You are advised to complete and return the form of proxy in accordance with the instructions printed on it so as to arrive at the Company's registrars, Neville Registrars Limited, Neville House, Steelpark Road, Halesowen, West Midlands, United Kingdom, B62 8HD as soon as possible, but in any event no later than 1:30 p.m. (London time) (8:30 a.m. Eastern Time) on Wednesday 31st May 2023. CREST members who wish to appoint a proxy or give an instruction through the CREST electronic proxy appointment service may do so by using the procedures described in the CREST manual.

If at any point you require guidance, please contact Neville Registrars Limited, by telephone at [phone], or by email at [e-mail].

ADS Holders

If you are a holder of ADS in the Company, please vote on the resolutions in accordance with the instructions set out at page 10 of this Notice of AGM. If you hold your ADSs through a bank, broker or nominee, a form of proxy for use by ADS holders will be sent to the brokerage firm, bank or nominee through which you hold your ADS.

Recommendation

You will find on pages 4 to 9 of this document an explanatory note in relation to each of the various resolutions which are set out in the Notice of AGM. Your Board consider that the proposed resolutions in the Notice of AGM are in the best interests of the Company and its shareholders as a whole and are most likely to promote the success of the Company. Accordingly, your Board unanimously recommend that shareholders vote in favour of the resolutions.

Thank you for your ongoing support of COMPASS Pathways.

Yours sincerely

George Goldsmith

Chairman

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EXPLANATORY NOTES TO THE BUSINESS OF THE AGM

Resolutions 1 through 10 (inclusive) will be proposed as ordinary resolutions under English law, assuming that a quorum is present, an ordinary resolution is passed on a show of hands if it is approved by a simple majority (more than 50%) of the votes cast by shareholders present (in person or by proxy) at the AGM and entitled to vote. If a poll is demanded, an ordinary resolution is passed if it is approved by holders representing a simple majority (more than 50%) of the total voting rights of shareholders present (in person or by proxy) who (being entitled to vote) vote on the resolution.

ORDINARY BUSINESS

Resolutions 1 to 4: Re-election of directors

Our Board of Directors currently consists of nine members. In accordance with the terms of our Articles of Association, our Board is divided into three classes, Class I, Class II and Class III, with members of each class serving staggered three-year terms. The members of the classes are divided as follows:

• the Class I directors are Ekaterina Malievskaia, David Norton and Wayne Riley and their terms will expire at the annual general meeting to be held in 2024;
• the Class II directors are Thomas Lönngren, Robert McQuade and Kabir Nath, and their terms will expire at the annual general meeting to be held in 2025; and
• the Class III directors are George Goldsmith, Annalisa Jenkins and Linda McGoldrick, and their terms will expire at the Meeting.

Upon the expiration of the term of a class of directors, directors in that class will be eligible to be elected for a new three-year term at the annual general meeting in the year in which their term expires.

Our Board of Directors has nominated George Goldsmith, Annalisa Jenkins and Linda McGoldrick for re-election as the Class III directors at the Meeting. Kabir Nath was appointed to the Board on 1st August 2022 and is designated as a Class II director. In accordance with our Articles of Association, Kabir will stand for re-election as a director at this year's annual general meeting, following which his term will expire in 2025 and he will be required to stand for re-election alongside the Board's other Class II directors.

The nominees are presently directors, and have indicated a willingness to continue to serve as directors, if elected. If the nominees become unable or unwilling to serve, however, the proxies may be voted for a substitute nominee selected by our Board.

In connection with Resolutions 1 to 4, we set forth the biographical information for the nominees to our Board. For biographical information for the other directors see Board of Directors and Corporate Governance in the Company's proxy statement.

Resolution 1

George Goldsmith

Non-Executive Director

George Goldsmith is currently the Chair of our Board of Directors and has been nominated for reelection as a director. If elected, he will hold office from the date of his election until the 2026 annual general meeting of shareholders where he must retire by rotation and offer himself for re-election, or until his earlier death, resignation or removal. Mr. Goldsmith has agreed to serve if elected, and we have no reason to believe that he will be unable to serve.

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George Goldsmith has served as Chair of our Board since June 2017 and served as our Chief Executive Officer from June 2017 to August 2022. Previously, Mr. Goldsmith served as Chair and Chief Executive Officer at Tapestry Networks, which he co-founded in 2002, until 2005, and he continues to serve as Non-Executive Chairman. Mr. Goldsmith was Chief Executive Officer of TomorrowLab@McKinsey from 2000 to 2001, and prior to that served as Senior Advisor to McKinsey & Company from 1997 to 2000. Prior to that he served as Managing Director of the Lotus Institute after the Lotus Development Corporation's acquisition of his first company, The Human Interface Group. Mr. Goldsmith also serves on the board of directors of our subsidiaries. Mr. Goldsmith received his bachelor's degree in Psychology from the University of Rochester and his masters in Clinical Psychology from the University of Connecticut. We believe that Mr. Goldsmith is qualified to serve on our Board because of his executive experience in our industry.

Resolution 2

Annalisa Jenkins

Non-Executive Director

Annalisa Jenkins is currently a member of our Board and has been nominated for re-election as a director. If elected, she will hold office from the date of her election until the 2026 annual general meeting of shareholders where she must retire by rotation and offer herself for re-election, or until her earlier death, resignation or removal. Dr. Jenkins has agreed to serve if elected, and we have no reason to believe that she will be unable to serve.

Annalisa Jenkins, MBBS, FRCP, has served as a member of our Board since May 2018. From November 2017 until April 2019, Dr. Jenkins served as the Chief Executive Officer of PlaqueTec Ltd., a biotechnology company focusing on coronary artery disease treatment and prevention. Previously, Dr. Jenkins served as the Chief Executive Officer and a member of the board of directors of Dimension Therapeutics, Inc., a gene therapy company focused on rare and metabolic diseases associated with the liver, from September 2014 until its sale to Ultragenyx Pharmaceutical Inc. in November 2017. From October 2013 to March 2014, Dr. Jenkins served as Executive Vice President, Head of Global Research and Development for Merck Serono Pharmaceuticals, a biopharmaceutical company. Previously, from September 2011 to October 2013, she served as Merck Serono's Executive Vice President, Global Development and Medical, and was a member of Merck Serono's executive committee. Prior to that, Dr. Jenkins pursued a 15-year career at Bristol-Myers Squibb Company, a biopharmaceutical company, where, from July 2009 to June 2011 she was a Senior Vice President and Head of Global Medical Affairs. Dr. Jenkins is currently a non-executive director of Genomics England. Dr. Jenkins serves on the board of directors of Avrobio, Inc. (Nasdaq: AVRO), Oncimmune Holdings plc (LSE: ONC), Affimed GmbH (Nasdaq: AFMD), Mereo BioPharma Group plc (Nasdaq: MREO) and a number of privately held biotechnology and life science companies. Previously within the past five years, Dr. Jenkins served on the board of directors of Ardelyx, Inc. (Nasdaq: ARDX) and AgeX Therapeutics, Inc. (NYSE American: AGE). Dr. Jenkins serves on a number of charitable boards, advisory boards and contributes publicly on leadership with purpose, social entrepreneurship, diversity and innovation. Dr. Jenkins graduated with a degree in medicine from St. Bartholomew's Hospital in the University of London and subsequently trained in cardiovascular medicine in the U.K. National Health Service. Earlier in her career, Dr. Jenkins served as a Medical Officer in the British Royal Navy during the Gulf Conflict, achieving the rank of Surgeon Lieutenant Commander. We believe Dr. Jenkins is qualified to serve on our Board based on her industry experience in the field in which we operate and her executive experience with companies in our industry.

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