Addex Successfully Completes $11.5 Million Capital Increase Including Full Exercise of Underwriter’s Option to Purchase Additional Securities

Geneva, Switzerland, January 11, 2021 – Addex Therapeutics Ltd (SIX: ADXN and Nasdaq: ADXN), a clinical-stage pharmaceutical company pioneering allosteric modulation-based drug discovery and development, announced today the successful completion of the previously announced global offering of 6,900,000 shares (New Shares) (including 6,750,000 shares delivered in the form of 1,125,000 American Depositary Shares, or ADSs) on the Nadaq Capital Market at a price of approximately CHF1.47 per share or $10.00 per ADS, including the full exercise of the underwriter’s option to purchase additional securities. Each ADS represents the right to receive six shares of Addex. The aggregate gross proceeds from the offering are $11.5 million, before deducting the underwriting discounts and commissions and offering expenses payable by Addex.

Addex intends to use the net proceeds from the global offering, together with cash on hand, mainly to advance development of its portfolio of proprietary drug candidates based on its allosteric modulator development capabilities. These include dipraglurant, an mGlu5 negative allosteric modulator, for use in Parkinson's disease and dystonia, and its preclinical pipeline.

H.C. Wainwright & Co. acted as sole book-running manager for the offering.

The New Shares are expected to begin trading on the SIX Swiss Exchange on January 12, 2021.

The shares, which are to be settled primarily in the form of ADSs, were offered and sold pursuant to the Company's previously filed registration statement on Form F-1 (File No. 333-251322), as amended, with the U.S. Securities and Exchange Commission (SEC) and declared effective by the SEC on January 6, 2021. The offering has been made by means of a prospectus. An electronic copy of the final prospectus may be obtained by contacting H.C. Wainwright & Co., LLC at 430 Park Avenue, 3rd Floor, New York, NY 10022, by telephone at [phone] or e-mail at [e-mail] or on the SEC’s website at SEC.gov.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy these securities, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction. There is no intention or permission to publicly offer, solicit, sell or advertise, directly or indirectly, any securities of Addex Therapeutics Ltd in or into Switzerland within the meaning of the Swiss Financial Services Act ("FinSA"). Neither this document nor any other offering or marketing material relating to these securities, such as the shares, constitutes or will constitute a prospectus pursuant to the FinSA, and neither this document nor any other offering or marketing material relating to the shares constitutes a prospectus pursuant to the FinSA, and neither this document nor any other offering or marketing material relating to the shares may be publicly distributed or otherwise made publicly available in Switzerland.