Abivax to Present Data on Obefazimod at United European Gastroenterology (UEG) Week 2026

Four oral presentations and three posters build upon Phase 3 ABTECT Maintenance and Induction programs in ulcerative colitis, long-term Phase 2 findings, and preclinical anti-fibrotic research

PARIS, France – September 30, 2026 – 10:05 PM CEST – Abivax SA (PARIS:FR, 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 seven scientific abstracts on obefazimod, its lead drug candidate for the treatment of moderately to severely active ulcerative colitis (UC), will be presented at the United European Gastroenterology (UEG) Week 2026 meeting, taking place October 17–20, 2026, in Barcelona, Spain. These presentations will highlight data from the Phase 3 ABTECT Maintenance and Induction trials in UC, long-term follow-up from the Phase 2 program in UC, and preclinical research on obefazimod's anti-fibrotic and anti-tumor activity.

"The data being presented at UEG Week add to the growing understanding of obefazimod and its potential in inflammatory bowel disease," said Marc de Garidel, MBA, Chief Executive Officer of Abivax. "These findings reinforce our confidence in obefazimod’s potential to address significant unmet needs for patients living with inflammatory bowel disease."

Chris Rabbat, PhD, Chief Medical Officer of Abivax, added, "The seven accepted abstracts reflect the breadth and maturity of the obefazimod program, spanning Phase 3 maintenance results, long-term Phase 2 efficacy and safety data, and preclinical findings on inflammation and fibrosis. We look forward to sharing these findings with the global gastroenterology community and highlighting the growing clinical and scientific evidence supporting obefazimod."

Visit the publications page of Abivax’s website to view the presentations after the conclusion of the meeting.

Data to be Presented:

Date & Time	Session	Room	Abstract #	Title	Presenter
Oral Presentation
October 19, 10:50–11:00	Hot Topics in Clinical GI Research	D3	OP097	Efficacy and safety of obefazimod in patients with moderately to severely active ulcerative colitis: results from the Phase 3, randomized, double-blind, placebo-controlled, 44-week maintenance trial (ABTECT-Maintenance)	Prof. Bruce E. Sands, MD, MS Professor of Medicine at Icahn School of Medicine at Mount Sinai
October 19, 10:50–11:00	Molecular Trajectories of Disease and Drug Responses in IBD	A1	OP091	Obefazimod increases miR-124 expression to consistently modulate inflammation and fibrosis across preclinical models	Prof. Silvio Danese, MD, PhD Professor of Gastroenterology and Director of Gastroenterology and Gastrointestinal Endoscopy Unit at IRCCS San Raffaele Hospital
October 19, 12:00–12:10	Long-term Outcomes of Interventional Trials in IBD	A2	OP107	Long-term efficacy and persistence with obefazimod after dose de-escalation to 25 mg: 3-year interim analysis in patients with moderately to severely active ulcerative colitis completing Week 144, stratified by prior advanced therapy experience: results from the Phase 2 program	Prof. Bruce E. Sands, MD, MS Professor of Medicine at Icahn School of Medicine at Mount Sinai
October 20, 12:20–12:30	Looking into the Future: Novel Therapeutics in IBD, Part 2	B3	OP260	Efficacy of obefazimod in Phase 3 ABTECT-Maintenance trial: results of 44-week therapy in subsets of patients with and without prior inadequate response to advanced therapies	Prof. Silvio Danese, MD, PhD Professor of Gastroenterology and Director of Gastroenterology and Gastrointestinal Endoscopy Unit at IRCCS San Raffaele Hospital
Moderated Poster
October 18, 17:24–17:30	Outcomes from RCT in IBD (II)	Hall 7 – Poster Stage 2	MP0294	Efficacy, persistence, and safety of obefazimod in patients with moderately to severely active ulcerative colitis: 3-year interim analysis following dose de-escalation to 25 mg in the open-label maintenance Phase 2 study	Bram Verstockt, MD, PhD Associate Professor and Principal Investigator at KU Leuven
October 18, 17:36–17:42	Outcomes from RCT in IBD (II)	Hall 7 – Poster Stage 2	MP0296	Symptoms of bowel urgency and nocturnal bowel movements are linked with improvement in clinical outcomes among patients with moderately to severely active ulcerative colitis treated with obefazimod: pooled results from the 8-week ABTECT Phase 3 induction trials	David T. Rubin, MD Professor of Medicine and Chief, Gastroenterology, Hepatology and Nutrition at The University of Chicago
E-Poster
October 17, 9:00 – 9:00	IBD, including microscopic colitis	Hall 7	PP1180	Obefazimod reduces inflammation-driven tumor burden in a murine model of colitis-associated cancer	Prof. Silvio Danese, MD, PhD Professor of Gastroenterology and Director of Gastroenterology and Gastrointestinal Endoscopy Unit at IRCCS San Raffaele Hospital

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 Baltz, PhD

Associate Director

LSC_ABIVAX@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," "on track," "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 potential therapeutic benefit of obefazimod and obefazimod’s potential to address significant unmet needs for patients living with inflammatory bowel disease, and other statements that are not historical fact. 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 for the fiscal year ended December 31, 2025 filed with the U.S. Securities and Exchange Commission on March 23, 2026, 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 labeling 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.

Attachment

2026_09_30_Abivax to Present Data on Obefazimod at UEG Week 2026