Abivax Announces Acceptance of 22 Abstracts Evaluating Obefazimod in Inflammatory Bowel Disease at ECCO 2026, Featuring an Oral Presentation on Preclinical Anti-Fibrotic Findings

Abivax Announces Acceptance of 22 Abstracts Evaluating Obefazimod in Inflammatory Bowel Disease at ECCO 2026, Featuring an Oral Presentation on Preclinical Anti-Fibrotic Findings

• Breadth of Scientific Evidence: The acceptance of 1 oral presentation, 5 digital oral presentations and 16 posters reflect an expanding dataset for obefazimod, including additional efficacy, safety, and cytokine data from the Phase 3 ABTECT Induction Trials in moderate-to-severely active ulcerative colitis (UC)
• Novel Anti-Fibrotic Preclinical Findings: Oral presentation on Saturday, February 21, 2026, “Obefazimod shows first evidence of anti-fibrotic activity in preclinical models of inflammatory bowel disease," will disclose new preclinical data addressing a critical complication in Crohn's disease (CD)

PARIS, France – December 17,  2025 – 10:05 pm CET – Abivax SA (Euronext Paris: FR0012333284 – ABVX / Nasdaq: ABVX) (“Abivax” or the “Company”), a clinical-stage biotechnology company focused on developing therapeutics that harness the body’s natural regulatory mechanisms to stabilize the immune response in patients with chronic inflammatory diseases, today announced that 22 scientific abstracts detailing advancements in the understanding of obefazimod for the treatment of inflammatory bowel disease (IBD) will be presented at The European Crohn’s and Colitis Organization’s (ECCO) 21st Annual Congress taking place February 18-21, 2026 in Stockholm, Sweden.

Subgroup Analyses from Phase 3 ABTECT Induction Trials

The accepted abstracts, based on subgroup analyses from ABTECT Induction Trials, illustrate obefazimod’s clinical activity across a wide range of patient subpopulations, demonstrate downregulation of pro-inflammatory cytokines (IL-17A, IL-6), and highlight early symptomatic improvement along with other clinically meaningful benefits. The data also reinforces obefazimod’s favorable tolerability profile.

Obefazimod Shows First Evidence of Activity in Preclinical Fibrotic Models

The upcoming oral presentation on anti-fibrotic activity addresses a significant unmet medical need in IBD. Fibrosis, or the excessive formation of scar tissue, is a serious complication, particularly in patients with CD. This scarring can lead to strictures (narrowing of the intestine) that often necessitate surgery. To date, no efficacious anti-fibrotic treatment is available for IBD patients.

The objective of the preclinical study was to assess the anti-fibrotic effects of obefazimod in an in vitro fibrosis model using human small-intestinal fibroblasts and in an in vivo TNBS-colitis mouse model. The data from this study, titled “Obefazimod shows first evidence of anti-fibrotic activity in preclinical models of inflammatory bowel disease,” will be presented during the oral presentation session on Saturday, February 21, 2026.

Marc de Garidel, Chief Executive Officer of Abivax, said “We are highly enthusiastic about the strong presence of obefazimod data at the 21st ECCO Congress, highlighting the impactful and robust data we have generated in inflammatory bowel disease. Presenting a total of 22 abstracts highlights the increasing depth of clinical understanding we have gained from the ABTECT Induction Trials in ulcerative colitis. This important data, along with the oral presentation highlighting the first evidence of anti-fibrotic activity in a preclinical model, demonstrates the potential for obefazimod to address a critical unmet need in IBD beyond inflammation.”

Fabio Cataldi, MD, Chief Medical Officer of Abivax, added, “Intestinal fibrosis is a major complication of Crohn’s disease that is not fully addressed by current therapies. This often leads to debilitating symptoms and the need for resection surgery. We look forward to sharing these new insights on obefazimod’s anti-fibrotic properties, alongside the expansive clinical data to demonstrate obefazimod’s potential efficacy and favorable safety profile in ulcerative colitis, with the IBD scientific community in Stockholm.”

Obefazimod Data to be Presented:

 
About Abivax

Abivax is a clinical-stage biotechnology company focused on developing therapeutics that harness the body’s natural regulatory mechanisms to stabilize the immune response in patients with chronic inflammatory diseases. Based in France and the United States, Abivax’s lead drug candidate, obefazimod (ABX464), is in Phase 3 clinical trials for the treatment of moderately to severely active ulcerative colitis.

Contact:

Patrick Malloy
SVP, Investor Relations
Abivax SA
patrick.malloy@abivax.com
1 847 987 4878

Media Contact:

LifeSci Communications
Karissa Cross, Ph.D.
Account Supervisor
kcross@lifescicomms.com

FORWARD-LOOKING STATEMENTS

This press release contains forward-looking statements, forecasts and estimates, including those relating to the Company’s business. Words such as “anticipate,” “expect,” “potential,” “will” and variations of such words and similar expressions are intended to identify forward-looking statements. These forward-looking statements include statements concerning the Company’s preclinical study results of obefazimod and the potential therapeutic benefit of obefazimod. Although Abivax’s management believes that the expectations reflected in such forward-looking statements are reasonable, investors are cautioned that forward-looking information and statements are subject to various risks, contingencies and uncertainties, many of which are difficult to predict and generally beyond the control of Abivax, that could cause actual results and developments to differ materially from those expressed in, or implied or projected by, the forward-looking information and statements. A description of these risks, contingencies and uncertainties can be found in the documents filed by the Company with the French Autorité des Marchés Financiers pursuant to its legal obligations including its universal registration document (Document d’Enregistrement Universel) and in its Annual Report on Form 20-F filed with the U.S. Securities and Exchange Commission on March 24, 2025 under the caption “Risk Factors.” These risks, contingencies and uncertainties include, among other things, the uncertainties inherent in research and development, future clinical data and analysis, decisions by regulatory authorities, such as the FDA or the EMA, regarding whether and when to approve any drug candidate, as well as their decisions regarding labelling and other matters that could affect the availability or commercial potential of such product candidates, and the availability of funding sufficient for the Company’s foreseeable and unforeseeable operating expenses and capital expenditure requirements. Special consideration should be given to the potential hurdles of clinical and pharmaceutical development, including further assessment by the Company and regulatory agencies and IRBs/ethics committees following the assessment of preclinical, pharmacokinetic, carcinogenicity, toxicity, CMC and clinical data. Furthermore, these forward-looking statements, forecasts and estimates are made only as of the date of this press release. Readers are cautioned not to place undue reliance on these forward-looking statements. Abivax disclaims any obligation to update these forward-looking statements, forecasts or estimates to reflect any subsequent changes that the Company becomes aware of, except as required by law. Information about pharmaceutical products (including products currently in development) that is included in this press release is not intended to constitute an advertisement. This press release is for information purposes only, and the information contained herein does not constitute either an offer to sell or the solicitation of an offer to purchase or subscribe for securities of the Company in any jurisdiction. Similarly, it does not give and should not be treated as giving investment advice. It has no connection with the investment objectives, financial situation or specific needs of any recipient. It should not be regarded by recipients as a substitute for exercise of their own judgment. All opinions expressed herein are subject to change without notice. The distribution of this document may be restricted by law in certain jurisdictions. Persons into whose possession this document comes are required to inform themselves about and to observe any such restrictions.