PARIS, France, September 29, 2023 – 11:00 p.m. (CEST) – Abivax SA (Euronext Paris: FR0012333284 – ABVX) (“Abivax” or the “Company”), a clinical-stage biotechnology company focused on the development of therapeutic treatments that exploit natural regulatory mechanisms of the body to modulate the immune response in patients suffering from chronic inflammatory diseases, announced today the filing of a Form F-1 registration document with the US Securities and Exchange Commission ( “SEC”) in connection with its proposed initial public offering in the form of American Depositary Shares (“ADSs”) representing ordinary shares in the United States (the “US Offering”) and a concurrent placement of its ordinary shares in Europe (including France) and other countries outside the United States (the “European Placement” and, together with the US Offering, the “Global Offering”). All securities sold as part of the Global Offering will be issued by the Company. The number of ordinary shares represented by each ADS, the number of ADSs and ordinary shares offered and the price range of the Global Offering have not yet been determined. The Global Offer is subject to market conditions and there can be no assurance as to whether or when the Global Offer will be completed. The Company has applied for admission of its ADSs to the Nasdaq Global Market under the symbol “ABVX”.