Ad Hoc Announcement Pursuant to Art. 53 LR 

Geneva, Switzerland, June 1, 2023 - Addex Therapeutics (SIX: ADXN and Nasdaq: ADXN), a clinical-stage pharmaceutical company pioneering allosteric modulation-based drug discovery and development (“the Company”), announced today that its shareholders approved, with a large majority, all of the proposals of the board of directors in its 2023 Annual General Meeting (AGM). The votes represented 32.24% of the company's outstanding capital.

Addex shareholders approved the 2022 annual report, the 2022 annual financial statements, the appropriation of the results as well as the compensation report (the latter in a consultative vote). All motions regarding the compensation of the board of directors and the executive management were also approved. In addition, discharge was granted to the members of the board of directors and the executive management for their activities during the business year 2022.

Dr. Vincent Lawton was re-elected as member and chairman of the board of directors and member of the compensation committee; Dr. Raymond Hill was re-elected as member of the board of directors and member of the compensation committee; and Dr. Roger Mills, Mr. Tim Dyer, Mr. Jake Nunn and Dr. Isaac Manke were re-elected as members of the board of directors.

BDO SA were re-elected as the auditors for the 2023 business year and Robert P. Briner, attorney-at-law, was re-elected as the independent voting rights representative until the 2024 Annual General Meeting.

Addex shareholders also approved the amendments of the Articles of Association. They approved the creation of a capital band, the increase of the conditional share capital, the possibility to grant loans to members of the Board of Directors and the Executive Management and the non-renewal of the exemption from the duty to make an offer granted to Growth Equity Opportunities Fund IV LLC and New Leaf Biopharma Opportunities on March 16, 2018, but expired on March 21, 2023.

The detailed agenda can be found on Addex’s website at https://www.addextherapeutics.com/en/investors/general-meetings/

About Addex Therapeutics:
Addex Therapeutics is a clinical-stage pharmaceutical company focused on the development and commercialization of an emerging class of novel orally available, small molecule drugs known as allosteric modulators for neurological disorders. Allosteric modulators offer several potential advantages over conventional, non-allosteric molecules and may offer an improved therapeutic approach to conventional "orthosteric" small molecule or biological drugs. Addex's allosteric modulator drug discovery platform targets receptors and other proteins that are recognized as essential for therapeutic intervention. Addex's lead drug candidate, ADX71149 (mGlu2 positive allosteric modulator or PAM), developed in collaboration with Janssen Pharmaceuticals, Inc., is in a Phase 2 clinical trial for the treatment of epilepsy. Addex's second clinical program, dipraglurant (mGlu5 negative allosteric modulator or NAM), is under evaluation for future development in a range of indications. Indivior PLC has licensed Addex’s GABAB PAM program for the development of drug candidates, with a focus on substance use disorder. Addex is also advancing a broad preclinical pipeline, which includes development of a range of GABAB PAMs for CMT1A, chronic cough and several types of pain, mGlu7 NAM for stress related disorders, mGlu2 NAM for mild neurocognitive disorders and depression, M4 PAM for schizophrenia and other forms of psychosis, as well as mGlu4 PAM and mGlu3 PAM. Addex shares are listed on the SIX Swiss Exchange and American Depositary Shares representing its shares are listed on the NASDAQ Capital Market, and trade under the ticker symbol "ADXN" on each exchange.

Contacts:

Tim Dyer Chief Executive Officer Telephone: +41 22 884 15 55 PR@addextherapeutics.com

Mike Sinclair Partner, Halsin Partners +44 (0)20 7318 2955 msinclair@halsin.com

Addex Forward Looking Statements:
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including statements about the intended use of proceeds of the offering. The words “may,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “project,” “potential,” “continue,” “target” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements in this press release, are based on management's current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, uncertainties related to market conditions. These and other risks and uncertainties are described in greater detail in the section entitled “Risk Factors” in Addex Therapeutics’ Annual Report on Form 20-F for the year ended December 31, 2022, as filed with the SEC on March 30, 2023, the final prospectus supplement and accompanying prospectus and other filings that Addex Therapeutics may make with the SEC in the future. Any forward-looking statements contained in this press release represent Addex Therapeutics’ views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date. Addex Therapeutics explicitly disclaims any obligation to update any forward-looking statements.