Abivax Presents First Evidence of Anti-Fibrotic Activity for Obefazimod Alongside New Clinical Efficacy and Safety Analyses in Inflammatory Bowel Disease at ECCO 2026

Rhea-AI Summary

Abivax (NASDAQ:ABVX) presented 22 abstracts at ECCO 2026 showing first preclinical evidence of anti-fibrotic activity for obefazimod and new clinical efficacy, safety, and biomarker data in inflammatory bowel disease.

Key findings: robust reductions in fibrosis markers (~45–90% in models), early symptomatic response by week 1 and remission by week 2, upregulation of miR-124, lowered IL-17A/IL-6, and comparable serious TEAE rates versus placebo in pooled Phase 3 induction data.

Positive

• Preclinical anti-fibrotic effects: Collagen deposition reduced ~45–55%
• Large model reductions in histologic fibrosis score: ~60–90%
• Early clinical symptomatic response: improvements from week 1
• Biomarker activity: significant miR-124 upregulation and IL-17A/IL-6 reduction
• Pooled Phase 3 safety: serious TEAE rates comparable to placebo (≈2–3%)

Negative

• Reported TEAEs led to study discontinuation up to 4.7% in some dosing arms
• Efficacy significance described as nominal by week 2, requiring confirmatory Phase 3 maintenance readout in Q2 2026

Key Figures

Number of abstracts: 22 abstracts Randomized patients: 1,272 patients Serious TEAEs rates: 3.1%, 2.2%, 3.2% +5 more

8 metrics

Number of abstracts 22 abstracts ECCO 2026 presentations on obefazimod in inflammatory bowel disease

Randomized patients 1,272 patients Phase 3 ABTECT induction safety analysis (Obe-50mg, Obe-25mg, placebo)

Serious TEAEs rates 3.1%, 2.2%, 3.2% Serious TEAEs for Obe-50mg, Obe-25mg, and placebo in ABTECT induction

Fibrosis biomarker reduction ~50% Pro-C3, ~30% αSMA In vitro human fibroblast model anti-fibrotic effects (p<0.0001)

Disease Activity Index reduction ~25% and ~50% Early (day 5) and late (day 20) treatment in animal model (p<0.0001)

Histologic fibrosis reduction ~60% and ~90% Histologic Fibrosis Score reduction with late and early treatment (p<0.0001)

Serious discontinuation TEAEs 4.7%, 1.9%, 4.1% TEAEs leading to discontinuation for Obe-50mg, Obe-25mg, placebo

p-values for miR-124 upregulation p<0.0001 vs placebo miR-124 expression increases in blood and tissue at week 8

Market Reality Check

Price: $130.35 Vol: Volume 735,505 vs 20-day ...

normal vol

$130.35 Last Close

Volume Volume 735,505 vs 20-day average 802,059 (about 8% below typical activity). normal

Technical Price 130.35 is trading above the 200-day MA at 76.21, reflecting a pre-existing uptrend.

Peers on Argus

ABVX was up 0.08% while key biotech peers like RYTM (-3.08%), NUVL (-2.74%) and ...

ABVX was up 0.08% while key biotech peers like RYTM (-3.08%), NUVL (-2.74%) and AXSM (-1.23%) generally traded lower, indicating a stock-specific reaction rather than a sector-wide move.

Historical Context

5 past events · Latest: Jan 07 (Positive)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Jan 07	Corporate outlook	Positive	+6.2%	2026 outlook with obefazimod timelines and extended cash runway guidance.
Dec 18	Index inclusion	Positive	+2.5%	Addition to Nasdaq Biotechnology Index tied to Phase 3 obefazimod progress.
Dec 17	Conference abstracts	Positive	-0.1%	Announcement of 22 ECCO 2026 abstracts including anti-fibrotic oral data.
Dec 15	Earnings/update	Negative	-6.1%	Q3 2025 losses and details on large equity raise despite strong cash balance.
Nov 03	Clinical outcomes	Positive	-3.5%	Phase 3 PRO data showing improved quality of life in ulcerative colitis.

Pattern Detected

ABVX has shown positive reactions to broad strategic/visibility updates, while some clinically positive releases have seen muted or negative price moves.

Recent Company History

Over the past few months, ABVX news has centered on advancing obefazimod in ulcerative colitis and Crohn’s disease, index inclusion, and strengthening its balance sheet. The Nasdaq Biotechnology Index addition and the 2026 corporate outlook each saw positive price reactions, while some favorable clinical data updates produced mixed trading responses. The latest ECCO 2026 data build directly on prior ABTECT and ENHANCE program disclosures from November 2025 and the January 7, 2026 outlook, reinforcing efficacy, safety, and mechanistic evidence in inflammatory bowel disease.

Market Pulse Summary

This announcement consolidates preclinical and clinical evidence around obefazimod in inflammatory b...

Analysis

This announcement consolidates preclinical and clinical evidence around obefazimod in inflammatory bowel disease, including anti-fibrotic signals, early symptomatic benefits, and miR-124–driven biomarker changes. The safety profile from 1,272 treated patients appears comparable to placebo, an important consideration for chronic use. Historically, ABVX has shown mixed price responses to positive clinical news, so investors may watch upcoming Phase 3 maintenance and Phase 2b Crohn’s readouts and any new financing or regulatory developments as key future catalysts.

Key Terms

anti-fibrotic, treatment emergent adverse events, p-value, miR-124, +4 more

8 terms

anti-fibrotic medical

"first evidence of anti-fibrotic activity for obefazimod..."

Anti-fibrotic describes a drug or therapy that slows, stops, or reverses fibrosis—the buildup of scar tissue in organs (such as lungs, liver, or heart) that stiffens tissue and reduces function. For investors, anti-fibrotic treatments matter because they address chronic conditions with large unmet needs and potential long-term markets; like repairing a clogged pipe before it bursts, successful therapies can preserve organ function, affect patient outcomes, and drive regulatory, clinical and commercial value.

treatment emergent adverse events medical

"rates of serious treatment emergent adverse events and study discontinuation..."

Treatment emergent adverse events are any new or worsened medical problems that appear after a patient starts a drug or medical intervention during a clinical trial. Investors care because the number, severity, and frequency of these events influence safety profiles, regulatory approval chances, and market acceptance; think of them like unexpected problems that crop up after installing a software update—minor ones may be manageable, but serious or common issues can stall or derail the product.

p-value technical

"symptomatic remission observed at week 2 (nominally significant p-value <0.05)..."

A p-value is a number that helps determine how likely it is that a result or pattern happened by chance rather than because of a real effect. For investors, a low p-value suggests that the findings in a study or analysis are probably meaningful and not just random noise—like noticing a pattern in coin flips that’s unlikely to occur by chance. This helps in assessing the reliability of information used to make financial decisions.

miR-124 medical

"upregulation of miR-124 and reduction of key inflammatory cytokines..."

mir-124 is a tiny piece of genetic material called a microRNA that helps turn genes up or down, especially in brain and nerve cells; think of it as a thermostat that adjusts how much a gene produces. Investors care because changes in mir-124 levels can signal disease, be used as a diagnostic marker, or become a drug target—factors that can influence clinical trial results, regulatory decisions, and the commercial value of therapies.

IL-17A medical

"reduction of key inflammatory cytokines (IL-17A and IL-6) toward homeostatic levels..."

IL-17A is a small signaling protein the immune system uses to call other immune cells to sites of inflammation, like a fire alarm that summons firefighters. It matters to investors because IL-17A is a proven drug target and biomarker in several inflammatory and autoimmune diseases; therapies that block or measure it can drive clinical trial success, regulatory approvals, marketable treatments, and therefore potential revenue and valuation changes for biotech and pharma companies.

IL-6 medical

"reduction of key inflammatory cytokines (IL-17A and IL-6) toward homeostatic levels..."

Interleukin-6 (IL-6) is a small signaling protein the body releases as an alarm during infection, injury, or chronic inflammation; think of it as a smoke detector that calls immune cells to action. It matters to investors because IL-6 levels can serve as a biomarker for disease severity and a target for therapies—drugs that block or modulate IL-6 can change treatment outcomes, regulatory decisions, and commercial prospects in healthcare markets.

ulcerative colitis medical

"moderately to severely active ulcerative colitis (Armuzzi A et al. P0923, ECCO 2026)..."

A long-term inflammatory disease that causes repeated sores and irritation in the large intestine, leading to symptoms such as abdominal pain, urgent diarrhea, and fatigue. For investors, it matters because the condition creates a steady need for effective treatments, influences the size of drug and medical-device markets, and makes clinical trial results, regulatory decisions and treatment approvals material to companies’ revenue prospects—like watching for fixes to a recurring leak in an important building system.

fibrosis medical

"emerging preclinical evidence of anti-fibrotic activity is particularly compelling, as fibrosis remains..."

Fibrosis is the process where excess scar tissue forms in an organ or tissue, often as a response to injury or long-term damage. This buildup can impair normal function, much like thickening insulation reduces the effectiveness of a wire. For investors, fibrosis is significant because it can signal ongoing health issues that may lead to increased medical costs or influence a company’s performance in healthcare-related sectors.

AI-generated analysis. Not financial advice.

Abivax Presents First Evidence of Anti-Fibrotic Activity for Obefazimod Alongside New Clinical Efficacy and Safety Analyses in Inflammatory Bowel Disease at ECCO 2026

• 22 abstracts presented at European Crohn’s and Colitis Organization’s (ECCO) 21^st Annual Congress illustrate the depth and breadth of data supporting obefazimod’s potential in inflammatory bowel disease
• Anti-fibrotic effects of obefazimod were observed in both a preclinical human fibroblast model and in an in vivo animal model, suggesting potential to address a major unmet need in Crohn’s disease
• A pooled analysis of safety data from ABTECT-1 and ABTECT-2 induction trials demonstrates a favorable safety profile with rates of serious treatment emergent adverse events and study discontinuation similar to placebo
• Symptomatic response of obefazimod was observed as early as week 1 (first time point evaluated) with symptomatic remission observed at week 2 (nominally significant p-value <0.05) in a pooled analysis of ABTECT-1 and ABTECT-2
• Biomarker data from ABTECT-1 and ABTECT-2 induction trials indicate upregulation of miR-124 and reduction of key inflammatory cytokines (IL-17A and IL-6) toward homeostatic levels
  
  

PARIS, France – February 21, 2026 – 12:00 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 novel preclinical and clinical data for obefazimod as part of the presentations at The European Crohn’s and Colitis Organization’s (ECCO) 21st Annual Congress. These data further expand the evidence base supporting development of obefazimod for inflammatory bowel disease, highlighting its anti-fibrotic potential in Crohn’s disease (CD), a favorable safety and tolerability profile, rapid onset of symptomatic relief, and additional evidence supporting its mechanism of action in restoring immune balance through upregulation of miR-124.

Marc de Garidel, MBA, Chief Executive Officer of Abivax, commented: "The robust data presented at ECCO this week reinforce obefazimod's unique and differentiated profile. The anti-fibrotic findings, taken together with the additional clinical efficacy, safety, and biomarker data presented, strengthen our confidence in obefazimod’s potential across UC and CD. As we look toward the upcoming Phase 3 maintenance trial readout in Q2 2026 and the Phase 2b ENHANCE-CD trial readout in Q4 2026, we remain focused on translating this data into real-world benefits for patients with IBD."

Fabio Cataldi, MD, Chief Medical Officer of Abivax, added: “The emerging preclinical evidence of anti-fibrotic activity is particularly compelling, as fibrosis remains an area of profound unmet need. Combined with the favorable safety and tolerability profile of obefazimod, we believe this growing evidence base positions obefazimod as a compelling oral therapy with the potential to address multiple dimensions of disease not yet fully managed by current therapies.”

HIGHLIGHTED PRESENTATIONS:

The 22 abstracts presented at ECCO 2026, including subgroup analyses from the Phase 3 ABTECT induction trials illustrating obefazimod’s clinical activity across a wide range of patient subpopulations, can be accessed at: https://www.abivax.com/publications/congress-publications

• Obefazimod shows first evidence of anti-fibrotic activity in preclinical models of inflammatory bowel disease (Danese S et al. OP30, ECCO 2026)
  • In an in vitro human fibroblast model, obefazimod led to a ~50% reduction in a biomarker of active fibrosis (Pro-C3) (p < 0.0001) and a ~30% reduction in a fibroblast activation marker (⍺SMA) (p < 0.0001)
  • In an in vivo animal model, obefazimod exhibited dual anti-inflammatory and anti-fibrotic effects leading to rapid improvement in markers of disease activity
    • Obefazimod demonstrated anti-inflammatory effects when initiated as a fibrosis preventative (day 5) or fibrosis treatment (day 20):
      • ~25% (p<0.0001) and ~50% (p<0.0001) reduction in Disease Activity Index, with late (day 20) and early (day 5) treatment, respectively
      • ~35% (p<0.0001) and ~65% (p<0.0001) reduction in histologic ulceration and inflammation scores, with late and early treatment, respectively
    • Obefazimod demonstrated anti-fibrotic effects when initiated as a fibrosis preventative (day 5) or fibrosis treatment (day 20):
      • ~45% (p<0.0001) and ~55% (p<0.0001) reduction in Collagen Deposition (fibrosis marker), with late and early treatment, respectively
      • ~40% (p<0.0001) and ~50% (p<0.0001) reduction in ⍺SMA (fibroblast activation marker), with late and early treatment, respectively

• ~60% (p<0.0001) and ~90% (p<0.0001) reduction in histologic Fibrosis Score, with late and early treatment, respectively

• Integrated summary of safety of obefazimod in Phase 3 ABTECT induction trials (Seidler U et al. P0712, ECCO 2026)
  • Of the 1,272 patients randomized and treated with Obe-50mg, Obe-25mg, or placebo (PBO), the overall rates of serious treatment emergent adverse events (TEAEs) was comparable across all groups (Obe-50mg: 3.1%; Obe-25mg: 2.2%; PBO: 3.2%)
  • TEAEs leading to study discontinuation occurred at similar rates across all groups (Obe-50mg, 4.7%; Obe-25mg, 1.9%; PBO, 4.1%)
  • Headaches were one of the most frequent TEAEs and were reported to be mild, transient, and short in duration (median: 2-3 days) and rarely leading to discontinuation (0-1.1%)
• Early symptomatic improvements with obefazimod in patients with moderately to severely active ulcerative colitis (Armuzzi A et al. P0923, ECCO 2026)
  • A greater proportion of patients receiving obefazimod (50mg or 25mg) versus PBO achieved symptomatic response from week 1 and symptomatic remission from week 2 increasing through week 8
  • In a pooled analysis of the Phase 3 ABTECT-1 and ABTECT-2 induction trials, both Obe-50mg and Obe-25mg produced reductions in rectal bleeding subscores and stool frequency subscores versus PBO starting from week 1 and reaching a nominally significant difference by week 2 (p-value <0.05)
  • Improvement in symptoms consistently increased through week 8

• Obefazimod enhances miR-124 expression in blood and colon tissue and reduces the key inflammatory cytokines IL-17A and IL-6 in serum of patients with moderately to severely active ulcerative colitis (Siegmund B et al. P0868, ECCO 2026)
  • In both Phase 3 ABTECT induction trials, Obe-25mg and Obe-50mg significantly enhanced expression of miR-124 in blood (unadjusted p < 0.0001 vs. PBO) and in rectal and sigmoidal tissue (unadjusted p < 0.0001 vs. PBO) at week 8
  • At week 8, Obe-25mg and Obe-50mg significantly reduced IL-17A levels in serum (unadjusted p < 0.0001 vs. PBO); Obe-25mg (p=0.0150 vs. PBO) and Obe-50mg (p=0.0039 vs. PBO) decreased IL-6 levels in serum
  • miR-124 mechanism of action allows for partial reduction of inflammatory cytokines IL-17 and IL-6 toward homeostatic levels without completely blocking these pathways

Professor Silvio Danese, Director of the Gastroenterology and Digestive Endoscopy Unit of the IRCCS San Raffaele Hospital, added: “For patients living with inflammatory bowel disease, long-term disease control and preservation of bowel function are critical. Seeing data that address not only clinical response and safety, but also biological activity and fibrosis, is encouraging. If these findings continue to translate clinically, they may represent a meaningful advancement for patients who currently have limited options.”

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 Contacts:

LifeSci Communications
Jon Pappas
SVP, Head of Media Relations
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,” “potential” 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 the expected availability and timing of results from the Phase 3 maintenance trial and Phase 2b ENHANCE-CD trial 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.

Attachment

• 20260221_Abivax_PR_Presents New Data at ECCO 2026

FAQ

What anti-fibrotic evidence did Abivax (ABVX) present for obefazimod at ECCO 2026?

Obefazimod showed preclinical anti-fibrotic activity with collagen deposition reduced ~45–55%. According to the company, animal and human fibroblast models reported large, statistically significant reductions in fibrosis markers (p<0.0001).

How quickly did obefazimod produce symptomatic improvements in ABVX Phase 3 trials?

Symptomatic response was observed from week 1 with remission by week 2 in pooled analyses. According to the company, reductions in rectal bleeding and stool frequency began at week 1 and reached nominal significance by week 2.

What safety profile did Abivax report for obefazimod (ABVX) in Phase 3 pooled data?

Pooled induction safety showed serious TEAE rates comparable to placebo (≈2–3%). According to the company, discontinuation rates were similar across arms, with most headaches mild and transient (median 2–3 days).

What biomarker changes did obefazimod produce in ABTECT trials for ABVX?

Obefazimod significantly increased miR-124 and lowered IL-17A and IL-6 by week 8. According to the company, both 25mg and 50mg doses showed unadjusted p<0.0001 versus placebo in blood and tissue measurements.

When are Abivax’s next clinical readouts for obefazimod (ABVX)?

Abivax expects a Phase 3 maintenance trial readout in Q2 2026 and the Phase 2b ENHANCE-CD readout in Q4 2026. According to the company, these readouts will further evaluate clinical efficacy and maintenance outcomes.