Mirikizumab in Ulcerative Colitis: JCC | June 2026

Introduction:

Mirikizumab, a selective IL-23p19 inhibitor, has demonstrated efficacy in phase III clinical trials for moderate-to-severe ulcerative colitis (UC). This multicenter Italian real-world study evaluated its effectiveness and safety in routine clinical practice, including patients previously exposed to multiple biologic therapies.

Why was this study needed?

Randomized trials often exclude complex patients with prior biologic failures and multiple comorbidities. Real-world data are essential to determine whether mirikizumab performs similarly in everyday clinical practice.

What did the study show?

• Nearly half of the patients achieved steroid-free clinical remission within 12 weeks.
• More than 60% achieved a meaningful clinical response after induction therapy.
• Clinical effectiveness was comparable in biologic-naïve and biologic-experienced patients.
• Prior ustekinumab exposure did not significantly reduce treatment effectiveness, although remission rates tended to be lower.
• Patients requiring extended induction had lower remission rates, suggesting more difficult-to-treat disease.
• Biochemical improvement in CRP and fecal calprotectin did not reach statistical significance during early follow-up.
• Mirikizumab demonstrated an excellent safety profile, with no treatment-related adverse events reported and only three patients discontinuing therapy because of lack of efficacy.

Clinical Impact:

These findings reinforce mirikizumab as an effective treatment option for moderate-to-severe UC in routine clinical practice, including patients with previous biologic exposure. The favorable safety profile and consistent clinical response support its use across a broad spectrum of patients.

Take-Home Message:

This real-world multicenter study confirms that mirikizumab is an effective and well-tolerated therapy for ulcerative colitis, achieving meaningful steroid-free remission even in biologic-experienced patients. These results support its growing role as an important IL-23–targeted treatment in everyday clinical practice.