Obefazimod Shows Remission Improvements in New Phase III Ulcerative Colitis Results

Abivax has shared new late-breaking results from its ongoing Phase III ABTECT induction trials for obefazimod, its leading investigational therapy for moderate-to-severe ulcerative colitis, during the United European Gastroenterology (UEG) Week 2025 in Berlin.

The data, presented on October 6, indicated that once-daily obefazimod 50 mg provided significant benefits for both patients with prior inadequate response to advanced therapies () and those starting such treatments for the first time.

These results build on earlier topline findings from July, reinforcing obefazimod’s potential as a next-gen oral treatment for ulcerative colitis, a disease where many patients still struggle to maintain long-term control, even with biologic or targeted drugs.

Ulcerative colitis is a chronic inflammatory bowel disease that causes ulcers and inflammation in the colon. Although newer therapies have improved disease management, many patients still do not achieve remission or may lose their response over time.

XTALKS WEBINAR: Boost Participant Recruitment with Precision Feasibility and RWD

Live and On-Demand: Monday, November 17, 2025, at 11am EST (5pm CET/EU-Central)

Register for this free webinar to explore actionable strategies that improve patient recruitment performance, optimize site selection and engage the right patients.

Obefazimod, also called ABX464, is an oral small molecule that aims to reduce intestinal inflammation by increasing levels of microRNA-124, a molecule that helps stabilize immune activity.

By focusing on this biological pathway, obefazimod seeks to reduce inflammation without broadly suppressing the immune system.

The pooled ABTECT 1 and 2 trials included 1,272 participants, nearly half of whom had previously shown AT-IR. About 60% of these participants had severe baseline disease, indicated by an endoscopic subscore of 3, and 21% had previously failed treatment with JAK inhibitors, which can be particularly challenging to treat.

In ulcerative colitis, an endoscopic subscore of 3 indicates severe inflammation visible during a colonoscopy, which likely includes ulcers, bleeding and extensive mucosal damage.

At Week 8, patients receiving the 50 mg dose of obefazimod experienced remission rates that increased by 10 percentage points compared to the placebo group (p=0.0009) among those whose disease was resistant to past treatments, and by 22 points (p<0.0001) in those who had not previously been treated. Clinical response rates followed a similar trend, improving by 28 points (p<0.0001) in participants without prior resistance, 29 points (p=0.0242) in those with at least four previous therapies and 34 points (p=0.0017) in patients who had previously failed JAK inhibitor treatment.

Here, a percentage point means that many more people out of every 100 achieved remission with the drug compared to those who received the placebo.

This is to say, patients treated with obefazimod seemed to show consistently higher remission and response rates than those on placebo, even among those with a history of multiple therapy failures.

Across subgroups, obefazimod also demonstrated improvements at both the endoscopic and tissue (histologic) levels, regardless of previous treatment history. Among patients without past therapy failures, both 25 mg and 50 mg doses produced similar results.

The treatment was generally well tolerated, and no unexpected side effects were reported in either dose group.

Abivax stated that obefazimod continues to show a favorable safety profile, supporting its potential use in a diverse range of ulcerative colitis patients.

The UEG Week presentations also included new data from other companies developing therapies for ulcerative colitis.

Johnson & Johnson presented additional Phase IIb findings for icotrokinra, an investigational oral peptide that blocks the IL-23 receptor, showing clinical response rates up to 63.5% at Week 12, with a favorable safety profile in the ANTHEM-UC trial.

Meanwhile, Eli Lilly showcased long-term Phase III data for its approved IL-23p19 antagonist Omvoh (mirikizumab), demonstrating sustained, corticosteroid-free clinical and endoscopic remission over four years in the LUCENT-3 extension study.

ABTECT’s findings strengthen Abivax’s late-stage program as the company continues to enroll patients in its Phase III maintenance trial for ulcerative colitis. This trial is expected to be the foundation for a planned New Drug Application (NDA) submission in 2026, pending regulatory feedback.

If you want your company to be featured on Xtalks.com, please email [email protected].