Oral Drug Helps Hard-to-Treat Ulcerative Colitis Patients Reach Remission

French biotech Abivax reported new data from its phase 3 ABTECT maintenance trial testing obefazimod, an oral, once-daily pill for ulcerative colitis, in one of the toughest patient populations a trial can study: people who did not respond to initial treatment or who relapsed after an early response. Ulcerative colitis is a chronic autoimmune disease that inflames the large intestine, and while several biologic drugs are approved for it, a meaningful share of patients either do not respond to their first treatment or lose their response over time. This group, sometimes called treatment-refractory, is usually excluded from the headline results of a drug trial, which makes this data set unusually useful. ABTECT is one of the larger phase 3 programs run in ulcerative colitis in recent years, giving the refractory-patient results here more statistical weight than a smaller study could provide.

Obefazimod works through a different mechanism than most approved ulcerative colitis drugs. It is a small molecule, taken as a pill rather than an infusion or injection, that boosts the activity of a molecule called miR-124, which in turn dials down the production of several inflammatory proteins involved in the disease. Because it is oral and does not directly suppress a single immune pathway the way antibody drugs do, it is being watched closely as a potentially simpler option for patients who want to avoid regular infusions.

In this second part of the ABTECT maintenance study, researchers followed patients who had not achieved clinical response after induction treatment or who relapsed during the earlier maintenance phase, then kept them on a continued 50 mg dose of obefazimod. By week 44, 37.2% of these induction non-responders reached clinical remission, and 34.5% achieved endoscopic remission, meaning follow-up colonoscopy showed the gut lining had substantially healed. For a patient population defined by not responding well to treatment, those numbers represent a meaningful outcome.

Beyond the efficacy numbers, the trial also expanded Abivax's long-term safety database for obefazimod, which matters because regulators scrutinize safety data especially closely for drugs intended for years of continuous use. Abivax has said it plans to submit a New Drug Application for obefazimod in ulcerative colitis to the FDA in the fourth quarter of 2026, and this expanded refractory-patient and safety data will likely form part of that submission. If approved, obefazimod would give doctors an oral option to offer patients who have already cycled through injectable or infused biologics without lasting success, a group that currently has few remaining choices. Because it is taken as a pill rather than requiring an infusion center visit or self-injection, it could also appeal to patients simply looking for a less disruptive way to manage a chronic illness that already demands a lot of their time and attention.