Mirikizumab Effective, Safe for Ulcerative Colitis

Mirikizumab appears effective and safe for the treatment of moderate to severely active ulcerative colitis (UC), according to research presented at the American College of Gastroenterology (ACG) 2021 Annual Meeting, held from October 22 to 27, 2021, in Las Vegas, Nevada and virtually.

This 52-week phase 2 trial enrolled adult patients with active UC (ClinicalTrials.gov Identifier: NCT02589665). Patients who responded to mirikizumab after a 12-week induction period were randomly assigned 1:1 to receive 200 mg mirikizumab subcutaneously every 4 weeks (n=47) or every 12 weeks (n=46).

Patients who reached week 52 without loss of clinical response either continued in maintenance to week 104 or were moved to a long-term extension study (ClinicalTrials.gov Identifier: NCT03519945) and received open-label mirikizumab at 200 mg every 4 weeks.

Clinical response was defined as achieving substantial reductions on the 9-point Mayo subscores for rectal bleeding, stool frequency, and endoscopy. Efficacy outcomes were reassessed at week 104. Safety signals were monitored throughout the trial duration.

At baseline, 40.9% of patients had total Mayo scores of 6 to 8; 59.1% had scores from 9 to 12. Of the 93 patients who responded to mirikizumab at week 12, 66 (70.9%) were in symptomatic remission at week 52. A total of 78 patients (83.9%) continued with mirikizumab through week 104.

At week 104, 59 (75.6%) patients were in symptomatic remission, 85.9% were in rectal bleeding remission, and 84.6% were in stool frequency remission. No significant differences in treatment response were observed between patients with prior biologics exposure and patients who were biologic-naïve. No new safety signals were observed, though 1 severe adverse event occurred: infection with Clostridioides difficile. One patient experienced worsening of UC on mirikizumab and discontinued treatment.

Results from this trial support the efficacy and safety of mirikizumab for up to 104 weeks of treatment. Symptomatic remission was sustained over the trial period. Further study of the drug is warranted to better illustrate its long-term effects.

Disclosure: All study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

Reference

Panaccione R, Feagan BG, Redondo I, et al. Efficacy and safety of mirikizumab in patients with ulcerative colitis: 104-week results from a phase 2 randomized controlled trial. Presented at: ACG 2021 Annual Meeting; October 22-27, 2021; Las Vegas, NV and virtual. Abstract P0563.