Abivax: Encouraging Clinical Results for Obefazimod
Abivax has announced positive results from Part 2 of the ABTECT maintenance trial, showing that its candidate obefazimod restores clinical remission in 37.2% of patients who did not respond to initial treatment, and in 45.5% of those who relapsed. The expansion of the safety base to 1,704 patient-years of exposure reveals that cancer incidence rates remain consistent with epidemiological benchmarks for ulcerative colitis, a key point ahead of the regulatory filing planned for the end of the year.
Sustained Efficacy in Challenging Populations
In patients who did not achieve a clinical response after 8 weeks of induction, continuing treatment with 50 mg of obefazimod for an additional 36 weeks resulted in clinical remission for 37.2% and endoscopic remission for 34.5% of patients at week 44. Meanwhile, 45.5% of patients who relapsed during the first part of the trial and received a dose increase to 50 mg regained clinical remission. These results demonstrate a consistent clinical benefit in clinically significant populations: initially non-responders and those who relapsed after responding. Abivax concludes that extending treatment and adjusting dosages are levers to expand therapeutic coverage, an argument that could support the regulatory dossier by broadening potential indications.
Overall Safety with No New Signals
The integrated analysis covering all phases 2 and 3 (1,704 patient-years of exposure) reveals adjusted cancer incidence rates: 0.35 events per 100 patient-years for cancers other than non-melanoma skin cancers (NMSC) in the combined cohort all dosages, and 0.64 in the 50 mg arm alone. For NMSC, observed rates are 0.59 and 0.64 respectively. Part 2 alone (most recent data) shows rates of 0.48 and 0.69 for non-NMSC cancers, and 0.95 and 0.69 for NMSC. The company emphasizes that all these rates fall within the expected epidemiological reference ranges for ulcerative colitis (0.30-0.70 for non-NMSC; 0.70-1.40 for NMSC). No new safety signals have emerged from prolonged exposure.
Regulatory Filing Confirmed Before End of 2026
Abivax confirms its timeline for filing a New Drug Application (NDA) with the FDA in the fourth quarter of 2026. Data from Part 2 enriches the integrated dossier presented in support of this application. The phase 2b ENHANCE-CD induction trial in Crohn's disease is set to publish its results in mid-2027, potentially opening a second therapeutic indication. For investors, the immediate issue concerns the reaction of regulatory authorities to the integrated dossier: does strengthening the safety base address previous concerns, or is there still a friction area that could slow down or condition the approval? The stock remains exposed to this regulatory risk before any decision by the FDA.
