mGluR7

Geneva, Switzerland, March 14, 2024 – Addex Therapeutics (SIX: ADXN), a clinical-stage pharmaceutical company pioneering allosteric modulation-based drug discovery and development, announced today that CEO, Tim Dyer, will present at the Bio-Europe Spring 2024 conference taking place March 18 - 20, 2024 in Barcelona, Spain. Dr. Robert Lütjens, Head of Discovery – Biology, will also be attending this event. In his presentation, Mr Dyer will provide a corporate update and discuss recent developments at Addex. Presentation Details: Date: Tuesday, March 19, 2024 Time: 11:00 - 11:15 CET Room: 133/134 Venue: International Barcelona Convention Center Mr Dyer and Dr Lütjens will be available for one-on-one meetings throughout the conference. For more information or to schedule a one-on-one meeting, please reach out through the conference online partnering system or contact IR@addexpharma.com. 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. The company’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 a range of GABAB PAM for chronic cough, mGlu7 NAM for stress related disorders, M4 PAM for schizophrenia and other forms of psychosis and mGlu2 NAM for mild neurocognitive disorders and depression. 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 7968 022075 msinclair@halsin.com 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.

Researchers report the results of the first ever genome-wide association study (GWAS) of a biosafety level 4 (BSL-4) virus. The team found two key human genetic factors that could help explain why some people develop severe Lassa fever, and a set of LARGE1 variants linked to a reduced chance of getting Lassa fever. The work could lay the foundation for better treatments for Lassa fever and other similar diseases. The scientists are already working on a similar genetics study of Ebola susceptibility. While combing through the human genome in 2007, computational geneticist Pardis Sabeti made a discovery that would transform her research career. As a then postdoctoral fellow at the Broad Institute of MIT and Harvard, Sabeti discovered potential evidence that some unknown mutation in a gene called LARGE1 had a beneficial effect in the Nigerian population. Other scientists had discovered that this gene was critical for the Lassa virus to enter cells. Sabeti wondered whether a mutation in LARGE1 might prevent Lassa fever -- an infection that is caused by the Lassa virus, is endemic in West Africa, and can be deadly in some people while only mild in others. To find out, Sabeti decided later in 2007, as a new faculty member at Harvard University, that one of the first projects her new lab at the Broad would take on would be a genome-wide association study (GWAS) of Lassa susceptibility. She reached out to her collaborator Christian Happi, now the Director of the African Center of Excellence for Genomics of Infectious Diseases (ACEGID) at Redeemer's University in Nigeria, and together they launched the study. Now, their groups and collaborators report the results of that study in Nature Microbiology -- the first ever GWAS of a biosafety level 4 (BSL-4) virus. The team found two key human genetic factors that could help explain why some people develop severe Lassa fever, and a set of LARGE1 variants linked to a reduced chance of getting Lassa fever. The work could lay the foundation for better treatments for Lassa fever and other similar diseases. The scientists are already working on a similar genetics study of Ebola susceptibility. The paper also describes the many challenges the team had to overcome during their 16-year collaborative effort, such as studying a dangerous virus and recruiting patients with a disease that is not well documented in West Africa. Dozens of scientists contributed to the work and spent seven years recruiting patients in Nigeria and Sierra Leone and many additional years establishing the research program and analyzing the results. "It truly took a village to get this done," said Happi, a co-senior author along with Sabeti. "Generations of people in our labs, across different institutions and countries, spent significant parts of their careers bringing this to fruition," added Sabeti, an institute member at the Broad, a Howard Hughes Medical Institute investigator, a professor at the Center for Systems Biology and the Department of Organismic and Evolutionary Biology at Harvard University, and a professor in the Department of Immunology and Infectious Disease at the Harvard T. H. Chan School of Public Health. The co-first authors of the study are Dylan Kotliar, an internal medicine resident at Brigham and Women's Hospital and an MD/PhD student in Sabeti's lab while the project was ongoing; Siddharth Raju, a graduate student in Sabeti's lab; Shervin Tabrizi, a postdoctoral researcher at the Broad; and Ikponmwosa Odia, a researcher at Irrua Specialist Teaching Hospital in Nigeria. Lassa learnings Sabeti recalls the team's early discussions when launching the project. They knew they had to be cautious at every step: To work with a BSL-4 virus, scientists must wear pressurized suits connected to HEPA-filtered air in a special containment lab. The virus causes fever, sore throat, coughing, and vomiting, but can quickly progress to organ failure in some people. "This was an extremely challenging study to get off the ground," said Kotliar, who worked on the project throughout his entire PhD in the Sabeti lab. "I think the battle scars, the things we've learned along the way about how to get a project like this done, are going to be important for future research into viruses in developing countries." Finding participants for the study would be challenging too. There are currently no FDA-approved diagnostics for Lassa, and Lassa virus cases are typically not documented. There are fewer than 1,000 cases reported each year in Nigeria, the most populous country where the virus is endemic, and cases are often in rural areas far from diagnostic centers, many of which don't have the technology to detect the virus. Infections with other viruses, and genomic complexity among different strains of the same Lassa virus can complicate analysis. Moreover, African populations have been historically underrepresented in past genetic studies, which reduces statistical power in data analyses and can make it difficult to identify key genetic variants. When Sabeti began thinking about how to start the project, she reached out to Happi, whom she knew through their mutual work on the malaria-causing pathogen, Plasmodium falciparum. With the help of collaborators including Peter Okokhere, a doctor treating Lassa patients at the Irrua Specialist Teaching Hospital, they began recruiting patients from both Nigeria and Sierra Leone. Then, they compared the genomes of about 500 people who'd had Lassa fever and nearly 2,000 who hadn't. In the Nigerian cohort, the team found that people with a set of variants in the LARGE1 gene -- which modifies a cell receptor that binds to certain viruses -- were less likely to get Lassa fever. Sabeti, Happi, and their colleagues also found genomic regions associated with Lassa fatality: in the LIF1 gene, which encodes an immune-signaling molecule, and, in the Nigerian cohort, the GRM7 gene, which is involved in the central nervous system. The team then used a large-scale screen called a massively parallel reporter assay to home in on which variants within these genomic regions might be functional and could be targets of new treatments. Better detection The researchers say that to improve detection and treatment of Lassa fever, more diagnostic centers and diagnostics that work in the field are needed, along with better health infrastructure to connect remote locations with major hospitals. "This really highlights the need for continued investment in understanding African population genetics," added Raju. "Even with a relatively limited sample set, we've increased our understanding of some African populations, specifically in immune-related genes -- and that shows how much more there is to do going forward." Sixteen years after they first started thinking about the genetics of Lassa fever, Sabeti and Happi are excited about the study's findings, which could explain the biological differences between mild and severe illness. They said the work also shows that, as thoughtful collaborations between countries, genome-wide association studies of BSL-4 viruses are possible. The researchers have already begun conducting a similar study of Ebola in Sierra Leone and Liberia, and other scientists are calling for increased pathogen surveillance and scientific training in Africa. "We're standing at a moment where we can actually start developing point-of-need diagnostics for Lassa virus and testing much more broadly," Happi said. "We need better infrastructure, but I think we've shown that this kind of study is a worthwhile pursuit." This work was supported in part by the National Institute of Health, the German Research Foundation, and the Howard Hughes Medical Institute.

Ad Hoc Announcement Pursuant to Art. 53 LR Geneva, Switzerland, January 31, 2024 – Addex Therapeutics (SIX: ADXN), a clinical-stage pharmaceutical company pioneering allosteric modulation-based drug discovery and development, announced today that the company has entered into an At The Market Offering Agreement (the “ATM Agreement”) with H.C. Wainwright & Co., LLC (“H.C. Wainwright”) with respect to an at-the-market offering program under which the Company may offer and sell, from time to time at its sole discretion, ADSs having an aggregate offering price of up to $2.1 million through H.C. Wainwright as its sales agent. The issuance and sale, if any, of the ADSs by the Company under the ATM Agreement will be made pursuant to the Company’s effective registration statement on Form F-3 (Registration Statement No. 333-255089). H.C. Wainwright may sell the ADSs by any method permitted by law deemed to be an “at the market offering” as defined in Rule 415(a)(4) of the Securities Act of 1933, as amended, including, without limitation, sales made through The Nasdaq Capital Market or on any other existing trading market for the ADSs. H.C. Wainwright will use commercially reasonable efforts to sell the ADSs from time to time, based upon instructions from the Company (including any price, time or size limits or other customary parameters or conditions the Company may impose). The Company will pay H.C. Wainwright a commission equal to three percent (3.0%) of the gross sales proceeds of any ADSs sold through H.C. Wainwright under the ATM Agreement, and also has provided H.C. Wainwright with customary indemnification and contribution rights. The Company is not obligated to make any sales of ADSs under the ATM Agreement. The Company or H.C. Wainwright may suspend or terminate the offering of ADSs upon notice to the other party and subject to other conditions. H.C. Wainwright will act as the sales agent on a commercially reasonable efforts basis consistent with its normal trading and sales practices and applicable state and federal law, rules and regulations and the rules of the Nasdaq Stock Market. The foregoing description of the ATM Agreement is not complete and is qualified in its entirety by reference to the full text of the ATM Agreement. 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. No sales of securities are being made under the ATM in Switzerland. 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. The company’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 a range of GABAB PAM for chronic cough, mGlu7 NAM for stress related disorders, M4 PAM for schizophrenia and other forms of psychosis and mGlu2 NAM for mild neurocognitive disorders and depression. 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 7968 022075msinclair@halsin.com Forward Looking StatementsThis 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.