Feb 22, 2023

NOT FOR DISTRIBUTION IN OR INTO THE UNITED STATES, AUSTRALIA, CANADA OR JAPAN OR TO U.S. PERSONS This financing was led by TCGX, with participation from existing investors Invus, Deep Track Capital, Sofinnova Partners, Venrock Healthcare Capital Partners, as well as from new investors Great Point Partners, LLC, Deerfield Management Company, Commodore Capital, Samsara BioCapital, Boxer Capital and others Proceeds to be primarily used for further advancing the obefazimod pivotal Phase 3 clinical trial program in ulcerative colitis, expanding the cash runway until the end of the second quarter of 2024 PARIS, FRANCE / ACCESSWIRE / February 22, 2023 / Abivax (Euronext Paris: FR0012333284 - ABVX) (the "Company"), a Phase 3 clinical-stage biotechnology company focused on developing therapeutics that modulate the immune system to treat patients with chronic inflammatory diseases, today announced the successful pricing of an oversubscribed EUR 130M financing with high-quality US and European biotech specialist investors (the "Investors"), led by TCGX, with participation from existing investors Invus, Deep Track Capital, Sofinnova Partners, Venrock Healthcare Capital Partners, as well as from new investors Great Point Partners, LLC, Deerfield Management Company, Commodore Capital, Samsara BioCapital, Boxer Capital and others, by way of a reserved capital increase of EUR 130M through the issuance of 20,000,000 newly-issued ordinary shares with a nominal value of EUR 0.01 per share (the "New Shares"), representing 89.6% of its current share capital, at a subscription price of EUR 6.50 per share (the "Capital Increase"). Prof. Hartmut J. Ehrlich, M.D., CEO of Abivax said: "We are excited to announce today's successful pricing of Abivax's oversubscribed capital increase of EUR 130M, with a balanced mix of top-tier existing and new investors, mostly US biotech specialists. We believe these new financial resources will allow us to move full steam ahead with our ongoing global clinical Phase 3 program of obefazimod for the treatment of ulcerative colitis. The recruitment of patients for this program is ongoing in the U.S. and the study centers in Europe, Latin America and Asia Pacific are expected to start including patients in the weeks and months to come. Based on our consistent Phase 2a and Phase 2b data, we expect that the Phase 3 studies will support the short- and long-term efficacy and safety profile of obefazimod. The Abivax team is fully focused on making obefazimod rapidly accessible to all the patients in need." Didier Blondel, CFO of Abivax, added: "We are extremely pleased to announce our successful EUR 130M capital increase at market price. Abivax, once again, could attract new top-tier US and European biotech investors, including Great Point Partners, LLC, Deerfield Management Company, Commodore Capital, Samsara BioCapital, Boxer Capital and a few additional great names, as well as most of our existing US and European biotech investors. We believe this proves that Abivax and obefazimod are not only recognized within the scientific and medical communities, but also among very specialized financial investors who believe in the potential of obefazimod as an effective treatment option for chronic inflammatory diseases, starting with ulcerative colitis. Based on our current assumptions, our cash runway has been extended until the end of the second quarter of 2024. These new financial resources will be mainly used to continue our Phase 3 clinical program. Besides our ambition to confirm obefazimod's potential as a long-lasting and effective treatment for patients in need, we continue to give particular attention to the maximization of shareholder value. We are committed to securing the full funding of our Phase 3 clinical program in due course through additional non-dilutive and dilutive financial resources."