Regulatory Decision Summary for Omvoh

The purpose of this New Drug Submission (New Active Substance) (NDS-NAS) was to seek market authorization for Omvoh (mirikizumab) for the treatment of adults with moderately to severely active ulcerative colitis who had failed previous conventional (i.e., corticosteroids, immunomodulators) or advanced (i.e., biologic, Janus kinase inhibitor) therapies.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by diffuse mucosal inflammation of the rectum and colon. The etiology of UC is unknown. Clinical symptoms include bloody diarrhea, rectal bleeding (RB), urgency, and tenesmus (a feeling of incomplete evacuation of the rectum after defecation). UC has a relapsing–remitting course, meaning that many patients have intermittent disease flares that are interspersed with periods of remission. A notable proportion of patients with moderately to severely active UC have an inadequate response to available treatments and/or are unable to maintain a response. In some patients, neither conventional nor targeted therapy is sufficiently effective to manage disease, necessitating surgical treatment with colectomy.

The benefits of Omvoh (mirikizumab) in the treatment of subjects with moderately to severely active UC who have previously failed conventional (i.e., corticosteroids, immunomodulators) or advanced (i.e., biologics, Janus kinase inhibitors) therapies for the treatment of UC were demonstrated in two phase 3, multicentre, randomized, double-blind, placebo-controlled studies designed to evaluate the efficacy and safety of mirikizumab as induction treatment (induction study), and as maintenance treatment (maintenance study; withdrawal design) in subjects who achieved clinical response during the previous induction study.

The induction study demonstrated that a greater proportion of subjects receiving an induction dosing regimen of mirikizumab 300 mg IV than placebo achieved improvement in signs and symptoms of UC following 12 weeks of treatment. The maintenance study demonstrated that among subjects who received Omvoh and achieved clinical response at Week 12 in the induction study, a greater proportion of subjects receiving maintenance dosing regimen of mirikizumab 200 mg SC than placebo achieved and maintained improvement in signs and symptoms of UC and were able to stop corticosteroid therapy. Additional benefits in favour of Omvoh were observed in endoscopic mucosal improvement, histologic-endoscopic mucosal improvement, and bowel movement urgency.

Based on the data submitted, the safety profile of Omvoh in subjects with UC is generally consistent with that previously established for other IL-23p19 inhibitor monoclonal antibodies marketed in Canada. Serious infections, severe liver injury, immune thrombocytopenia (ITP), MACE, and malignancies have emerged as a potential safety issues. At this time, given the uncertainties that remain in the characterization of the risks in this proposed UC indication, the Biologic and Radiopharmaceutical Drugs Directorate (BRDD) has included a statement in the product monograph regarding a contraindication for active severe infection and a recommendation to monitor liver enzymes as clinically indicated. The risks of MACE, malignancies, and ITP will be monitored through pharmacovigilance activities.

Overall, based on the data and information evaluated as part of this assessment, the BRDD considers there to be a favourable benefit-risk profile for Omvoh (mirikizumab) in support of the authorized indication for the treatment of adults with moderately to severely active UC who have had an inadequate response, loss of response, or were intolerant to conventional therapy, a biologic treatment, or a Janus kinase (JAK) inhibitor.