mGluR4

Geneva, Switzerland, August 3, 2023 – Addex Therapeutics (SIX and Nasdaq: ADXN), a clinical-stage pharmaceutical company pioneering allosteric modulation-based drug discovery and development, today announced that it will issue its Half-Year 2023 Financial Results on August 10, 2023. Tim Dyer, CEO, Robert Lütjens, Head of Discovery – Biology and Mikhail Kalinichev, Head of Translational Science, will provide a business update and a review of the Addex product pipeline during a teleconference and webcast for investors, analysts and media at 16:00 CEST (15:00 BST / 10:00 EDT / 07:00 PDT) the same day. Title: Addex Therapeutics to Announce Half-Year 2023 Financial Results and Provides Corporate Update Date: August 10, 2023Time: 16:00 CEST (15:00 BST / 10:00 EDT / 07:00 PDT) Joining the Conference Call: Participants are required to register in advance of the conference using the link provided below. Upon registering, each participant will be provided with Participant Dial-in numbers, and a unique Personal PIN.In the 10 minutes prior to the call’s start time, participants will need to use the conference access information provided in the e-mail received at the point of registering. Participants may also use the call me feature instead of dialing the nearest dial in number. Online Registration: https://register.vevent.com/register/BI3df82968423c4258930719a84f76d6bf Webcast URL: https://edge.media-server.com/mmc/p/gp4h8rth 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 DyerChief Executive OfficerTelephone: +41 22 884 15 55PR@addextherapeutics.comMike SinclairPartner, Halsin Partners+44 (0)7968 022075msinclair@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.

Discovery collaboration on track to deliver clinical candidates for IND enabling studies in 2024 Ad Hoc Announcement Pursuant to Art. 53 LR Geneva, Switzerland, August 3, 2023 - Addex Therapeutics (SIX and Nasdaq: ADXN), a clinical-stage pharmaceutical company pioneering allosteric modulation-based drug discovery and development, today announced that its collaboration agreement with Indivior PLC (LON: INDV) for the discovery of novel oral gamma-aminobutyric acid subtype B (GABAB) positive allosteric modulator (PAM) drug candidates for the treatment of substance use disorder has been extended until June 30, 2024. As part of the extended agreement, Indivior has committed CHF 2.7 million to support research and discovery activities during this period. Addex retains exclusive rights to advance its own independent GABAB PAM program and is developing compounds for the treatment of chronic cough. “We are excited to continue working closely with Indivior in this promising application of our allosteric modulator discovery platform,” said Tim Dyer, CEO of Addex. “Indivior’s commitment to the substance use disorder program demonstrates the solid progress being made in the advancement of promising GABAB PAM candidates with the optimal characteristics needed for success in the clinic.” About GABAB Activation with PAM:Activation of gamma-aminobutyric acid subtype B (GABAB) receptor, a Family C class of GPCR, is clinically and commercially validated. The generic GABAB receptor agonist, baclofen, marketed for spasticity and some spinal cord injuries, has been shown to be efficacious in several other disease areas, including alcohol use disorder, CMT1A, chronic cough and pain. However, its wider use is limited due to a variety of side effects, rapid clearance and the development of tolerance. Novel, potent, selective and orally available positive allosteric modulators (PAMs) that potentiate GABA responses, rather than acting as orthosteric agonists at the GABAB receptor, like baclofen, are expected to deliver efficacy and have fewer adverse effects. Furthermore, PAMs only act when the natural ligand (GABA) activates the receptor, hence respecting the physiological cycle of activation, which may explain why PAMs lead to less tolerance than direct agonists. 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 post-stroke recovery. 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 GABAB PAM for chronic cough, M4 PAM for schizophrenia and other forms of psychosis, mGlu7 NAM for stress related disorders, mGlu2 NAM for mild neurocognitive disorders and depression, 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 DyerChief Executive OfficerTelephone: +41 22 884 15 55 PR@addextherapeutics.com Mike SinclairPartner, Halsin Partners+44 (0)20 7318 2955msinclair@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.

Data published in Neuropharmacology shows mGlu2 PAMs attenuate oxycodone use and potential as a novel treatment for opioid use disorder Ad Hoc Announcement Pursuant to Art. 53 LR Geneva, Switzerland, July 24, 2023 - Addex Therapeutics (SIX and Nasdaq: ADXN), a clinical-stage pharmaceutical company pioneering allosteric modulation-based drug discovery and development, today announced data showing that administration of a metabotropic glutamate 2 (mGlu2) positive allosteric modulator significantly reduces oxycodone self-administration in preclinical models, supporting a potential role in opioid use disorder. The data were published in Neuropharmacology by Addex and The Scripps Research Institute. “In the United States, opioid abuse and overdose have reached epidemic proportions, with oxycodone being the most abused prescription opioid. Research suggests that glutamate release elicits drug-seeking behaviors, which suggests targeting the glutamate system with novel pharmacotherapies could alleviate these cravings,” said Dr. Rémi Martin-Fardon from The Scripps Research Institute, the paper’s lead author. “Our research demonstrates that using an mGlu2 PAM to decrease glutamate activity can stop oxycodone self-administration and seeking in preclinical models, which supports this approach as a future potential treatment of prescription opioid use disorder.” Study DetailsThe aim of the study was to test whether the mGlu2 receptor positive allosteric modulator ADX106772 could reduce oxycodone self-administration and the conditioned reinstatement of oxycodone seeking without affecting behaviors directed toward a highly palatable non-drug reinforcer (sweetened condensed milk, SCM). Rats were trained to self-administer oxycodone (0.15 mg/kg/infusion, i.v.,12 h/day) or sweetened condensed milk for 13 days in the presence of a contextual/discriminative stimulus (SD). Oxycodone, SCM, and the SD were then withheld. Once oxycodone or SCM self-administration was acquired and oxycodone dependence verified, the effect of ADX106772 (0.3, 1, 3, or 10 mg/kg, s.c.) was tested on oxycodone or SCM self-administration. ADX106772 was found to reduce oxycodone self-administration and conditioned reinstatement without affecting SCM self-administration or conditioned reinstatement. ADX106772 reduced oxycodone taking and seeking but did not affect the motivation for the palatable conventional reinforcer. “The results of this study add to existing research supporting targeting mGlu2 receptors with PAMs to counter drug use and seeking. In previous research, this approach has successfully been used in nicotine, cocaine and alcohol models,” said Dr. Robert Lütjens, Head of Discovery – Biology at Addex. “Demonstrating the wide potential of mGlu2 PAMs, an Addex discovered drug candidate, ADX71149, is being evaluated in a phase 2 clinical study as a potential treatment for epilepsy by our partner Janssen.” 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. About Scripps ResearchScripps Research is an independent, nonprofit biomedical institute ranked one of the most influential in the world for its impact on innovation by Nature Index. We are advancing human health through profound discoveries that address pressing medical concerns around the globe. Our drug discovery and development division, Calibr, works hand-in-hand with scientists across disciplines to bring new medicines to patients as quickly and efficiently as possible, while teams at Scripps Research Translational Institute harness genomics, digital medicine and cutting-edge informatics to understand individual health and render more effective healthcare. Scripps Research also trains the next generation of leading scientists at our Skaggs Graduate School, consistently named among the top 10 US programs for chemistry and biological sciences. Learn more at www.scripps.edu. Contacts: Tim DyerChief Executive OfficerTelephone: +41 22 884 15 55PR@addextherapeutics.comMike SinclairPartner, Halsin Partners+44 (0)7968 022075msinclair@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.