Abivax Strengthens Commercial Capabilities With Strategic Leadership Appointments

Appointed industry leaders bring decades of experience across commercial strategy, patient services, launch readiness, and field force development

PARIS, France – July 23, 2026 – 10:05 p.m. 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 the expansion of its Commercial Leadership Team with four strategic appointments spanning marketing, patient services, sales, commercial operations, and market access. These additions strengthen Abivax's commercial organization as the Company prepares for the potential U.S. commercialization of obefazimod, including a planned New Drug Application ("NDA") submission to the U.S. Food and Drug Administration ("FDA") in the fourth quarter of 2026.

Michael Nesrallah, MBA, Chief Commercial Officer of Abivax, said: "As we prepare for the potential commercialization of obefazimod, we are strengthening our Commercial Leadership Team with accomplished executives who bring deep expertise in inflammatory bowel disease, immunology, specialty product launches, and commercial execution. Collectively, they have helped build and grow some of the industry's leading brands in gastroenterology and immunology and will play a critical role in preparing Abivax for a potential U.S. launch."

COMMERCIAL LEADERSHIP TEAM ADDITIONS

James Berger – Global Head of Marketing

James is a seasoned commercial biopharmaceutical executive with more than 20 years of experience leading U.S. and global brand strategy, product launches, and lifecycle management across immunology, gastroenterology, respiratory, and oncology. As Global Head of Marketing at Abivax, he leads commercial strategy and brand development for obefazimod.

Prior to joining Abivax, James served as Global Franchise Head for TEZSPIRE^® at Amgen, where he led global brand strategy and franchise growth. Before Amgen, he spent more than a decade at Takeda helping shape the strategy, launch, and growth of ENTYVIO^® into one of the world's leading inflammatory bowel disease brands. Earlier in his career, he held commercial leadership roles at Amgen, Merck, and Bristol Myers Squibb.

Ivan Nuñez-Pacheco – Global Head of Patient Services

Ivan is a patient services and customer experience executive with more than 25 years of experience building and leading patient support organizations across the pharmaceutical and life sciences industries. As Global Head of Patient Services at Abivax, he leads the development of the Company's patient services model for obefazimod.

Before joining Abivax, Ivan served as Senior Director of AbbVie Patient Services, where he led the patient engagement organization supporting HUMIRA^®, SKYRIZI^®, and RINVOQ^®, with additional oversight across oncology and neuroscience. Under his leadership, the organization evolved into a centralized model delivering millions of patient interactions annually while supporting launch readiness and care model innovation.

Heather Dean – Global Head of Sales, Accounts & Commercial Operations

Heather brings more than 25 years of commercial leadership experience spanning sales, marketing, operations, and commercial management across multiple therapeutic areas. As Global Head of Sales, Accounts & Commercial Operations, she leads Abivax's sales, account management, and commercial operations strategy.

During her career at Eli Lilly and Takeda, Heather supported the launch of more than a dozen products. At Takeda, she led the pre- and post-launch commercial teams for ENTYVIO^® in ulcerative colitis and Crohn's disease before serving as Senior Vice President of the Neuroscience Business Unit, overseeing a 350-person organization across marketing, analytics, and field sales.

Jeff Haas – Global Head of Market Access & Pricing

Jeff brings nearly 30 years of healthcare leadership experience across pharmaceuticals and diagnostics. As Global Head of Market Access & Pricing, he is responsible for developing market access and pricing strategies to support the potential commercialization of obefazimod.

Before joining Abivax, Jeff served as Corporate Vice President at Abbott Laboratories, where he led the Infectious Disease Developed Markets business through the COVID-19 pandemic. Previously, during nearly 22 years at Abbott and AbbVie, he held senior leadership roles spanning market access, pricing, neuroscience, oncology, and specialty products. His experience includes leading market access and pricing strategy for the launch of HUMIRA^®, expanding patient access, and helping establish AbbVie's oncology and neuroscience commercial organizations.

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

Media Contact:

LifeSci Communications

Karissa Baltz, Ph.D.

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 be a first-in-class therapy for ulcerative colitis, the timing of regulatory filings including an NDA submission for obefazimod in ulcerative colitis, the potential U.S. commercialization of obefazimod, 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.

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2026_07_23_Abivax Strengthens Commercial Capabilities