Mirikizumab is the IL-13 Targeting Medication for Ulcerative Colitis
Mirikizumab (Omvoh) is the medication approved for ulcerative colitis that targets the IL-13 pathway, specifically by blocking the p19 subunit of interleukin-23, which regulates IL-13 production. 1, 2
Mechanism of Action
- Mirikizumab is a humanized IgG4-variant monoclonal antibody that binds to the p19 subunit of interleukin-23 (IL-23), thereby blocking the IL-23 pathway which regulates downstream inflammatory cytokines including IL-13 3, 4
- This represents a distinct mechanism from TNF-α antagonists, integrin inhibitors, JAK inhibitors, and sphingosine-1-phosphate modulators 3
Guideline Positioning
- The 2024 AGA guidelines suggest the use of mirikizumab over no treatment for moderate-to-severe UC (conditional recommendation, moderate certainty of evidence) 1
- Mirikizumab is classified as an intermediate-efficacy medication in both biologic-naïve and biologic-experienced patients 1
- In biologic-naïve patients, the AGA suggests using higher-efficacy medications (infliximab, vedolizumab, ozanimod, etrasimod, upadacitinib, risankizumab, guselkumab) or intermediate-efficacy medications (golimumab, ustekinumab, tofacitinib, filgotinib, mirikizumab) rather than lower-efficacy options 1
- In biologic-experienced patients (particularly TNF-exposed), mirikizumab remains an intermediate-efficacy option alongside filgotinib, risankizumab, and guselkumab 1
Clinical Efficacy Data
Induction Phase (Week 12):
- Clinical remission achieved in 24.2% of mirikizumab-treated patients versus 13.3% with placebo (P<0.001) in the LUCENT-1 trial 2
- Clinical response rates of 59.7% with the 200mg dose versus 20.6% with placebo 4
- Endoscopic remission and histologic-endoscopic mucosal remission were significantly superior to placebo 2, 5
Maintenance Phase (Week 52):
- Clinical remission maintained in 49.9% of mirikizumab patients versus 25.1% with placebo (P<0.001) in LUCENT-2 2
- Glucocorticoid-free clinical remission and improvement in bowel urgency were significantly achieved 2, 5
Dosing Regimen
- Induction: 300 mg intravenously every 4 weeks for 12 weeks 2, 5
- Maintenance: 200 mg subcutaneously every 4 weeks 2, 5
Safety Profile
- Common adverse events include nasopharyngitis (7.2%), injection-site reactions (8.7%), arthralgia, and headache (3.3%) 2, 5
- Among 1217 patients treated with mirikizumab, 15 had opportunistic infections (including 6 with herpes zoster) and 8 had cancer (including 3 with colorectal cancer) 2
- The selective IL-23 inhibition mechanism may confer a lower rate of infectious complications compared to TNF antagonists 6
Clinical Considerations
- Mirikizumab is effective in both biologic-naïve and biologic-experienced patients, though positioned as intermediate-efficacy in current guidelines 1, 5
- The medication demonstrated durable efficacy throughout the 52-week maintenance period 4, 2
- Quality of life improvements were significant across multiple validated instruments including IBDQ, SF-36, and EQ-5D-5L scores 7