In a recent report in Gastroenterology, researchers investigated the safety and efficacy of mirikuzimab in patients with moderate-to-severe Crohn’s disease (CD). According to investigators, “mirikuzimab effectively induced endoscopic response after 12 weeks in patients with moderate-to-severe CD and demonstrated durable efficacy to Week 52.”

A total of 191 patients were enrolled in the phase 2 trial and randomized 2:1:1:2 to groups to receive intravenous (IV) placebo, 200, 600, or 1000 mg mirikuzimab every 4 weeks. Patients who received mirikizumab and achieved a ≥1 point in improvement in Simple Endoscopic Score-CD were rerandomized into maintenance cohorts which received either continued IV treatment, or subcutaneous 300 mg mirikizumab. The primary outcome of the study was to compare mirikizumab to placebo in achieving endoscopic responses, defined as a 50% reduction from baseline at Week 12.

Reportedly, the number of endoscopic responses was significantly higher for all of the mirikizumab groups when compared with placebo (200 mg: 8/31 [25.8%], 95% confidence interval [CI], 10.4–41.2; p = .079; 600 mg: 12/32 [37.5%], 95% CI, 20.7–54.3; p = .003; 1000 mg: 28/64 [43.8%], 95% CI, 31.6–55.9; p <.001; and placebo: 7/64 [10.9%], 95% CI, 3.3–18.6). In the follow-up cohorts, the continued IV group had an endoscopic response rate of 58.5% (24/41) and the subcutaneous group had a rate of 58.7% (27/46). Adverse events were comparable between the treatments and placebo group.

In closing, the investigators summarized that “IL23p19 blockade with mirikizumab results in early improvement in endoscopic and clinical outcomes with demonstration of durable long-term efficacy.” They pointed to the ongoing research on mirikuzimab in CD in the VIVID trial series.