TOPLINE:

Mirikizumab induced a clinical response in 70.3% of patients with moderate-to-severe ulcerative colitis (UC), including those who were previously exposed to other treatments; however, rates of clinical remission and steroid-free remission were modest (< 20%).

METHODOLOGY:

• Previous studies have shown mirikizumab’s significant efficacy over placebo, but real-world data remain limited, particularly in treatment-refractory populations.
• Researchers conducted a two-center retrospective observational study of adults with moderate-to-severe UC who initiated mirikizumab before May 2025 at two tertiary referral centers for inflammatory bowel disease in Israel and the Czech Republic.
• Participants received a standard dose of 300 mg mirikizumab intravenously at weeks 0, 4, and 8, followed by a 200-mg dose subcutaneously every 4 weeks for maintenance.
• Clinical disease activity was assessed using the Simple Clinical Colitis Activity Index (SCCAI) at baseline and 12 weeks post-induction, with clinical response defined as ≥ 3-point reduction in the SCCAI score and clinical symptomatic remission defined as having an SCCAI score ≤ 2.
• The primary outcome was the rate of clinical symptomatic remission after a 12-week induction, with secondary outcomes assessing clinical response, corticosteroid-free remission, C-reactive protein and fecal calprotectin remission, endoscopic response, and adverse events.

TAKEAWAY:

• Among 74 treated patients (median age at UC diagnosis, 26 years; 58.1% women), 70.3% achieved a clinical response, 17.6% clinical symptomatic remission, and 16% corticosteroid-free remission.
• Overall, 93% had previous exposure to advanced therapy. Clinical response and remission rates were comparable between patients previously exposed to anti-TNF agents and anti-TNF-naive patients, with comparable rates for vedolizumab, ustekinumab, and JAK inhibitors.
• Median fecal calprotectin levels decreased significantly from 951 μg/g at baseline to 202 μg/g after induction (P = .007). Patients with baseline SCCAI scores < 6 achieved higher rates of clinical remission than those with higher scores (30.3% vs 9.8%; P = .036).
• A younger age at mirikizumab initiation was associated with greater odds of achieving a clinical response (adjusted odds ratio, 0.94; P = .023), even adjusting for prior exposure to advanced therapy.
• After completing induction, 8.1% of patients discontinued therapy due to lack of efficacy or adverse events.

IN PRACTICE:

“Although the modest rates of clinical remission indicate the need to develop more combination strategies to enhance deeper control of inflammation, the high rates of clinical response observed, along with a favorable safety profile, position mirikizumab as a valuable addition to the evolving landscape of UC management,” the authors wrote.

SOURCE:

The study was led by Asaf Levartovsky, Sheba Medical Center, Ramat Gan, Israel. It was published online in Therapeutic Advances in Gastroenterology.

LIMITATIONS: 

The retrospective design and small sample size limited robustness and subgroup analyses. The 12-week follow-up prevented evaluation of long-term efficacy and safety. Clinical response and remission were based solely on SCCAI, and only a few patients had endoscopic data. Temporal trends during the induction period could not be fully assessed.

DISCLOSURES:

The study received no specific funding. Few authors reported receiving speaker fees, consulting fees, advisory board fees, research support, and/or honoraria from various pharmaceutical, biopharmaceutical, or medical device companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.