Understanding What Class of Drug Is Mirikizumab?

October 8, 2025 •

3 min read

In October 2023, the U.S. Food and Drug Administration (FDA) approved Omvoh (mirikizumab-mrkz) for the treatment of moderately to severely active ulcerative colitis in adults. Understanding what class of drug is mirikizumab reveals its targeted approach to treating inflammatory bowel diseases (IBD) by inhibiting a key pathway responsible for chronic inflammation.

Quick Summary

Mirikizumab, known by the brand name Omvoh, is a biologic medication belonging to the drug class of monoclonal antibodies and, more specifically, interleukin-23 antagonists. It is prescribed for adults with moderately to severely active ulcerative colitis and Crohn's disease.

Key Points

Monoclonal Antibody: Mirikizumab is a monoclonal antibody, a laboratory-produced protein designed to interfere with a specific target in the body's immune system.
IL-23 Antagonist: More specifically, mirikizumab works as an interleukin-23 (IL-23) antagonist, blocking the activity of the IL-23 cytokine that fuels inflammation.
Targeted Action: This biologic drug selectively inhibits the IL-23p19 subunit, providing a targeted approach to reducing inflammation.
Therapeutic Indications: Mirikizumab is approved for treating moderately to severely active ulcerative colitis and Crohn's disease in adults.
Administration Protocol: Treatment involves an initial intravenous induction phase followed by self-administered subcutaneous injections for maintenance.
Safety Considerations: Patients must be screened for tuberculosis (TB) before starting therapy, and live vaccines should be avoided during treatment.
Long-term Efficacy: Clinical trials have shown mirikizumab provides durable efficacy, with long-term remission rates and improved mucosal healing for IBD patients.

What is Mirikizumab?

Mirikizumab, marketed under the brand name Omvoh, is a prescription biologic medicine used to treat moderate to severe inflammatory bowel diseases (IBD). It is administered via injection, with an initial intravenous (IV) induction phase followed by a subcutaneous (SC) maintenance phase. Mirikizumab targets a specific part of the inflammatory response and is used for conditions like ulcerative colitis (UC) and Crohn's disease (CD) by focusing on a specific signaling molecule that drives intestinal inflammation.

What Class of Drug is Mirikizumab?

Mirikizumab is classified as a monoclonal antibody and an interleukin inhibitor. As a biologic, it is a protein-based medication.

Monoclonal Antibody: The 'mab' suffix in mirikizumab's name indicates it is a monoclonal antibody. These are laboratory-produced antibodies, and mirikizumab is specifically a humanized immunoglobulin G4 (IgG4) monoclonal antibody.
Interleukin Inhibitor (IL-23 Antagonist): Mirikizumab is an interleukin inhibitor, or an IL-23 antagonist. It targets and blocks the p19 subunit of the interleukin-23 (IL-23) cytokine, which promotes inflammation in the GI tract for IBD.

How Mirikizumab Works: The Mechanism of Action

Mirikizumab selectively inhibits the IL-23 pathway. In IBD, the immune system is overactive, and IL-23 is crucial in driving inflammation.

Mirikizumab binds to the p19 protein subunit of IL-23.
This blocks IL-23 from activating its receptor on immune cells.
This inhibits the IL-23 pathway, preventing the release of pro-inflammatory cytokines.
This reduces chronic inflammation in the intestinal lining in conditions like ulcerative colitis and Crohn's disease.

Studies show this approach can lead to clinical and endoscopic remission.

Therapeutic Uses: Targeting Inflammatory Bowel Disease

Mirikizumab is approved for treating two types of IBD in adults:

Ulcerative Colitis

FDA approval for moderate to severe UC was granted in October 2023. Phase 3 trials (LUCENT program) showed mirikizumab's effectiveness in achieving and maintaining remission, even in those who failed previous biologics. It showed sustained efficacy over multiple years.

Crohn's Disease

In January 2025, mirikizumab received FDA approval for moderate to severe CD in adults. The VIVID-1 phase 3 trial demonstrated efficacy, showing significant remission and endoscopic response compared to placebo. Long-term studies confirmed its durable efficacy and safety for CD patients.

Comparison of Mirikizumab with Other Biologics

Mirikizumab is an IL-23p19 antagonist. Here is a comparison with other common biologics:


Feature	Mirikizumab (Omvoh)	Ustekinumab (Stelara)	Adalimumab (Humira)
Drug Class	IL-23p19 Antagonist	IL-12/IL-23p40 Antagonist	TNF-alpha Inhibitor
Target	Specifically blocks the p19 subunit of IL-23	Blocks the shared p40 subunit of both IL-12 and IL-23	Blocks Tumor Necrosis Factor-alpha (TNF-α)
Mechanism	Inhibits the upstream inflammatory pathway driven by IL-23	Broader inhibition of both IL-12 and IL-23 inflammatory pathways	Inhibits a different inflammatory cytokine, TNF-α
Administration	IV induction followed by SC maintenance every 4 weeks	IV induction followed by SC maintenance every 8 weeks	Subcutaneous injections, often every 2 weeks
Indications	UC and CD	UC, CD, psoriasis, psoriatic arthritis	UC, CD, RA, psoriasis, others
Safety Profile	Monitored for infections, TB, and liver function	Monitored for infections and other risks similar to biologics	Monitored for serious infections, malignancy

Important Safety Information and Considerations

Patients on mirikizumab require safety monitoring. Prior to treatment, and regularly during, patients are screened for latent tuberculosis (TB). Other warnings for Omvoh include:

Serious Infections: Increased risk of serious infections. Monitor for symptoms.
Hepatotoxicity: Liver injury reported; check liver enzymes before and during treatment.
Hypersensitivity Reactions: Severe allergic reactions possible. Evaluate immediately if symptoms appear.
Immunizations: Avoid live vaccines. Complete age-appropriate vaccinations before starting therapy.

Conclusion

Mirikizumab (Omvoh) is a targeted biologic, a monoclonal antibody, and an interleukin-23p19 antagonist. By blocking the IL-23 pathway, it addresses the inflammatory drivers of UC and CD, offering a therapeutic option for adults with moderate to severe disease. Its approval is a notable development for IBD treatment, especially for patients unresponsive to other therapies. Patients should discuss this treatment with their healthcare provider. For more information, consult the prescribing information.

Further Resources

Drugs.com: Mirikizumab Information

Frequently Asked Questions

The brand name for mirikizumab is Omvoh, and it is manufactured by Eli Lilly and Company.

Mirikizumab is an IL-23p19 antagonist, targeting a specific inflammatory pathway upstream. Other biologics, like adalimumab, target TNF-alpha, while ustekinumab targets both IL-12 and IL-23 via the p40 subunit.

Treatment begins with intravenous infusions, typically at weeks 0, 4, and 8. The maintenance phase transitions to subcutaneous injections every 4 weeks, which can be self-administered.

Mirikizumab (Omvoh) is approved for the treatment of moderately to severely active ulcerative colitis and moderately to severely active Crohn's disease in adults.

Common side effects include upper respiratory infections, injection site reactions, headache, and joint pain.

Mirikizumab can increase the risk of serious infections, including tuberculosis (TB). Patients should be screened for TB before starting treatment and monitored for signs of infection.

Live vaccines should be avoided during treatment with mirikizumab. It is important to complete all age-appropriate vaccinations according to current guidelines before starting therapy.

Mirikizumab blocks inflammation by binding to the p19 protein subunit of the interleukin-23 cytokine, thereby inhibiting the inflammatory signaling pathway in the gut.

As of its recent approvals, there is no generic or biosimilar version of mirikizumab available.