Abivax SA (PARIS:FR) ("Abivax" or the "Company"), a clinical-stage biotechnology company focused on developing therapeutics that harness the body's natural regulatory mechanisms to modulate the inflammatory response in patients with chronic inflammatory diseases, today announced the implementation of an At-The-Market program ("ATM Program") allowing the Company to issue and sell, including with unsolicited investors who have expressed an interest, ordinary shares in the form of American Depositary Shares ("ADS"), each ADS representing one ordinary share, nominal value €0.01 per share, of the Company, with aggregate gross sales proceeds of up to $150,000,000 (subject to French regulatory limits and within the limits of the investors' requests expressed in the context of the program), from time to time, pursuant to the terms of an equity distribution agreement with Piper Sandler & Co. ("Piper Sandler"), acting as sales agent. The timing of any issuances in the form of ADSs will depend on a variety of factors. The ATM Program will be effective for a 3-year period, i.e. until November 19, 2027, unless terminated prior to such date in accordance with the equity distribution agreement or if ADSs representing the maximum gross sales proceeds have been sold thereunder.