Addex Increases Issued Share Capital to Create Treasury Shares

Geneva, Switzerland, April 26, 2021 - Addex Therapeutics Ltd (SIX: ADXN and Nasdaq: ADXN), a clinical-stage pharmaceutical company pioneering allosteric modulation-based drug discovery and development, today announced that it has increased its share capital from 39,748,635 to 49,272,952 through the issue of 9,524,317 new registered shares at a nominal value of CHF1 each to Addex Pharma S.A, its 100% wholly-owned subsidiary. The new shares, issued from the Company’s authorized capital, are listed on the SIX Swiss Exchange. The transaction has been executed to provide the Group with additional future financing flexibility.

“This transaction provides us with financing flexibility as we advance two programs into clinical trials, including our lead program dipraglurant for Parkinson’s disease levodopa-induced dyskinesia, and four programs towards IND-enabling studies,” said Tim Dyer, CEO of Addex. “We also look forward to the start of our third clinical program, ADX71149 for epilepsy which is being executed by our partner, Janssen Pharmaceuticals Inc.”

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 product candidate, dipraglurant (mGlu5 negative allosteric modulator or NAM), is poised to start a pivotal registration clinical trial for Parkinson’s disease levodopa induced dyskinesia (PD-LID) in Q2 2021. Addex is also investigating dipraglurant's therapeutic use in blepharospasm (a type of dystonia), for which a clinical trial is expected to be initiated in Q2 2021. Addex's third clinical program, ADX71149 (mGlu2 positive allosteric modulator or PAM), developed in collaboration with Janssen Pharmaceuticals, Inc., is scheduled to enter a phase 2a proof of concept clinical trial for the treatment of epilepsy in Q2 2021. Addex’s GABAB PAM program has been licensed to Indivior PLC, which is focused on development for the treatment of addiction. Preclinical programs include GABAB PAM for CMT1A, mGlu7 NAM for PTSD, mGlu2 NAM for mild neurocognitive disorders, mGlu4 PAM for Parkinson’s disease and mGlu3 PAM for neurodegenerative disorders. 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.

Press Contacts:

Tim DyerChief Executive Officer+41 22 884 15 [e-mail]

Mike SinclairPartner, Halsin Partners+44 (0) 20 7318 [e-mail]

James CarbonaraHayden IR(646)[e-mail]

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 in respect of the anticipated initiation and progress of clinical trials and preclinical studies, and its future financing activities. 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 the Company’s Annual Report on Form 20-F filed with the SEC on March 11, 2021, as well as market conditions and regulatory review.

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, except as required by law.