Abivax to show phase 3 and preclinical obefazimod findings in inflammatory bowel disease at ECCO 2026

Abivax SA 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.

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

• 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.