Positive long-term results from the RELIEVE UCCD extension study have shown that duvakitug, an investigational monoclonal antibody targeting TL1A, maintained durable clinical and endoscopic efficacy for up to 44 weeks in patients with Ulcerative Colitis (UC) and Crohn’s disease (CD) who initially responded to treatment.

The double-blind, randomised long-term extension study evaluated the safety, tolerability and sustained efficacy of duvakitug in the two most common forms of Inflammatory Bowel Disease (IBD). A total of 130 patients who responded during the 14-week phase IIb induction trial were re-randomised to receive either 450 mg or 900 mg of subcutaneous duvakitug every four weeks, for up to 58 weeks of total exposure.

At week 44 of the maintenance phase, 58 percent of UC patients receiving 900 mg and 47 percent receiving 450 mg achieved clinical remission as measured by the modified Mayo score. Among CD patients, 55 percent in the 900 mg group and 41 percent in the 450 mg group achieved endoscopic response based on the Simple Endoscopic Score for Crohn’s Disease (SES-CD). Consistent benefits were observed across additional efficacy endpoints in both conditions.

Houman Ashrafian, Executive Vice President and Head of R&D at Sanofi, said, “These results reinforce duvakitug's potential as a leading TL1A therapy and an important advancement in inflammatory bowel disease treatment with durable efficacy maintained for nearly one year.” He further noted that phase III studies are currently underway.

Eric Hughes, Executive Vice President, Global R&D and Chief Medical Officer at Teva Pharmaceutical Industries, said sustaining response remains a key challenge in IBD treatment and described TL1A as a compelling therapeutic target.

Both doses of duvakitug were generally well tolerated. The most common adverse events, occurring in at least 5 percent of patients, included upper respiratory tract infection, nasopharyngitis, Crohn’s disease flare and hypertension. The safety profile was consistent with findings from the earlier phase IIb induction study. Detailed data will be presented at an upcoming medical meeting.

IBD, which includes UC and CD, is a chronic autoimmune disorder marked by persistent gastrointestinal inflammation, affecting an estimated 4.9 million people globally. Current treatments aim to induce and maintain remission, as no cure is available.

Duvakitug is currently in phase III clinical development. The therapy works by selectively inhibiting TL1A-DR3 signalling, a pathway believed to amplify inflammation and contribute to fibrosis in IBD.

Sanofi and Teva are co-developing and co-commercialising duvakitug, sharing development costs and profits in major markets. Sanofi is leading the global phase III programme, while Teva will lead commercialisation in Europe and select regions.

The safety and efficacy of duvakitug have not yet been reviewed by regulatory authorities.