PARIS, France, June 29, 2026
Abivax SA announced positive topline results from ABTECT Maintenance Part 2, the supplemental portion of its Phase 3 clinical trial evaluating obefazimod in adults with moderately to severely active ulcerative colitis (UC). The study met its objective of expanding both the efficacy and long-term safety database in a highly refractory patient population, demonstrating that continued treatment with 50 mg obefazimod produced meaningful clinical remission and endoscopic improvements in patients who had previously failed to respond during induction therapy.
According to the company, 37.2% of induction non-responders achieved clinical remission, while 61.5% achieved clinical response, 48.0% experienced endoscopic improvement, 44.6% reached Histologic-Endoscopic Mucosal Improvement (HEMI), and 34.5% achieved endoscopic remission after continued treatment through Week 44. These findings reinforce the potential of obefazimod to provide sustained disease control even in patients with difficult-to-treat ulcerative colitis who typically have limited therapeutic options.
Dose Escalation Successfully Recaptured Clinical Remission Following Relapse
The ABTECT Maintenance Part 2 trial also evaluated patients who experienced disease relapse after participating in Maintenance Part 1, demonstrating that increasing treatment intensity could effectively restore disease control. Patients who had initially responded to obefazimod during induction but later relapsed after switching to placebo achieved a 69.7% clinical response rate and 45.0% clinical remission rate following re-treatment with 50 mg obefazimod. Similarly, patients who relapsed while receiving the 25 mg dose and were escalated to 50 mg achieved a 66.7% clinical response rate and 45.5% clinical remission rate.
Improvements were also observed across important endoscopic endpoints, including endoscopic improvement, HEMI, and endoscopic remission, supporting the use of dose escalation as a practical strategy for regaining long-term disease control. Investigators noted that these findings demonstrate continued therapeutic benefit beyond initial induction and provide clinicians with greater flexibility when managing patients who experience relapse during maintenance therapy.
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Expanded Phase 3 Safety Data Reinforces Favorable Long-Term Benefit-Risk Profile
Beyond efficacy, the trial substantially expanded the long-term safety database supporting obefazimod. Abivax presented integrated analyses from its combined Phase 2 and Phase 3 ulcerative colitis development program, representing approximately 1,704 patient-years of exposure. The analysis showed that exposure-adjusted incidence rates (EAIRs) for malignancies excluding non-melanoma skin cancer (NMSC) remained between 0.35 and 0.64 events per 100 patient-years, while NMSC incidence ranged from 0.59 to 0.64 events per 100 patient-years, remaining consistent with published background rates for ulcerative colitis patients.
Within Maintenance Part 2, four NMSC events and two non-NMSC malignancies were reported, with investigators determining that the malignancies were unrelated to obefazimod treatment and that affected patients possessed well-established cancer risk factors, including advanced age, prior thiopurine exposure, previous skin cancer history, and multiple prior advanced therapies. Importantly, no new safety signals emerged, and the overall safety profile remained consistent with earlier studies, further strengthening confidence in the investigational therapy’s long-term tolerability and supporting its favorable benefit-risk profile.
Positive Clinical Results Support Planned FDA NDA Submission Later This Year
Abivax believes the comprehensive efficacy and safety findings from ABTECT Maintenance Part 2, together with previously reported positive Phase 3 maintenance results, provide a robust clinical package supporting its planned New Drug Application (NDA) submission to the U.S. Food and Drug Administration (FDA) in the fourth quarter of 2026. Company leadership stated that the expanded maintenance data demonstrate clinically meaningful benefit across a broad spectrum of ulcerative colitis patients, including highly refractory populations, while strengthening confidence in obefazimod’s long-term safety profile.
If approved, obefazimod has the potential to become a first-in-class oral miR-124 enhancer capable of offering durable disease control through a novel immune-regulating mechanism. Beyond ulcerative colitis, Abivax continues advancing its broader inflammatory disease pipeline, including the ongoing Phase 2b ENHANCE-CD clinical trial evaluating obefazimod in Crohn’s disease, with topline results anticipated in mid-2027. The company remains focused on completing regulatory submissions and expanding the clinical evidence supporting obefazimod as a potential new treatment option for patients living with chronic inflammatory bowel diseases.
Source: Abivax, press release
