Phase 2 data shows benefit for mirikizumab in CD patients

Patients with Crohn’s disease (CD) treated with mirikizumab for induction therapy experienced improvements to clinical and endoscopic outcomes.

“Mirikizumab is a humanised immunoglobulin G4 monoclonal antibody, and it binds to the p19 subunit of IL-23,” Prof. Bruce Sands (Icahn School of Medicine at Mount Sinai, New York, USA) began his presentation [1]. “We assessed the safety and efficacy of mirikizumab with a phase 2, multicentre, randomised, parallel-arm, double-blind, placebo-controlled trial in patients with moderate-to-severe CD.” Mirikizumab has also shown some success in treating ulcerative colitis and psoriasis.

Researchers randomly assigned 191 patients to receive either 200 mg (n=31), 600 mg (n=32), or 1,000 mg (n=64) of mirikizumab versus placebo (n=64) intravenously at weeks 0, 4, and 8. The primary outcome of the study was to determine the superiority of mirikizumab over placebo at week 12, as assessed by at least 50% reduction of the validated Simple Endoscopic Score for CD (SES-CD). Secondary outcomes were clinical remission and CD activity index.

At week 12, the 200 mg group achieved a 25.8% endoscopic response rate (95% CI 10.4–41.2, not significant), the 600 mg group achieved a 37.5% response rate (95% CI 20.7–54.3; P=0.032), and the 1,000 mg group achieved a 43.8% response rate (95% CI 31.6–55.9; P=0.009), whereas in the placebo arm only 10.9% of patients achieved endoscopic response (95% CI 3.3–18.6). Clinical remission assessed by patient-reported outcomes was also greater in treatment groups compared with placebo (12.9%, 28.1%, and 21.9% vs 6.3%, respectively). All 3 treatment groups showed greater response regarding CD activity index (200 mg: P=0.015; 600 mg: P=0.001; 1,000 mg: P=0.026).

The safety findings of the study did not reveal any new signals from the safety profile known for mirikizumab, with the frequency of serious and treatment-emergent adverse events in all 3 treatment arms similar to placebo.

1. Sands BE et al. UEG Week 2019, Abstract OP166.

Posted on 23 October 20198 April 2024