Mirikizumab

Mirikizumab, a monoclonal antibody targeting the p19 subunit of IL-23, will likely be first-in-class for ulcerative colitis and the third in the class approved for Crohn’s disease. Part of a set of emerging therapies with novel mechanisms of action, it will contribute to the growing market share held by these therapies and potentially more efficacious and long-lasting treatment options for patients.

About mirikizumab

Eli Lilly and Company
Humanized IgG4 monoclonal antibody
Monthly intravenous or subcutaneous administration to treat Crohn’s disease and moderately-to-severely active ulcerative colitis
Crohn’s disease: ~1.8 million diagnosed prevalent cases in the G7 markets in 2021
Ulcerative colitis: ~2.3 million diagnosed prevalent cases in the G7 markets in 2021

Why is it a drug to watch?

Based on positive phase 2 results for patients with Crohn’s disease (significant reductions in disease severity and increased rates of remission), mirikizumab advanced into the following phase 3 studies:
• VIVID-1: mirikizumab vs ustekinumab or placebo in patients 15 to 80 years old with moderate-to-severe disease; with a primary completion date in December 2023, expected to serve as the basis for regulatory filings in the United States, Europe and Japan
• VIVID-2: long-term extension study to evaluate efficacy and safety
Positive results from the phase 3 LUCENT 1 induction study (vs placebo) with patients with moderate-to-severe ulcerative colitis showed improvement as early as four weeks and, at 12 weeks, met its primary and all key secondary endpoints of:
• Clinical remission
• Endoscopic remission
• Symptomatic remission
• Reduced bowel urgency
• Clinical response
• Improvement in endoscopic histologic inflammation
The phase 3 LUCENT-2 study followed LUCENT-1 participants for one year and showed:
• nearly two-thirds of participants maintained clinical remission at one year and
• nearly all participants with clinical remission at one year were not taking corticosteroids for at least three months prior to the end of maintenance treatment.
These results were regardless of previous failure to TNF inhibitors, tofacitinib or other biologics. Ongoing phase 3 studies include:
• LUCENT-3: long-term extension study to evaluate efficacy and safety
• SHINE-1: evaluating mirikizumab in pediatric participants (aged 2-17 years)

Review and approval status

Ulcerative colitis

March 2022:
• Biologics License Application (BLA) submission: U.S. Food and Drug Administration (FDA)
• Marketing authorization application submission: European Medicines Agency (EMA)

Q2 2022:
• Marketing authorization submission: Japan’s Ministry of Health, Labor and Welfare (MHLW)

Expected launch:
• Crohn’s disease – 2025: United States, Japan and Europe
• Ulcerative colitis – 2023: United States, Japan and Europe

Patents estimated to expire beginning in 2034

How will mirikizumab impact the market for Crohn’s disease and ulcerative colitis?

Because treatments for Crohn’s disease and ulcerative colitis vary significantly in potency, onset of action, side effect profile and route of administration, symptom severity and remission status contribute to drug selection.
Growth in the market for both diseases will most likely driven by increasing uptake of ENTYVIO® and STELARA® and approval and uptake of premium-priced emerging therapies, including mirikizumab.
Entry of the biosimilar ustekinumab could temper sales of competing therapies.
Several novel agents, including mirikizumab, are launching for both diseases within the next couple of years, making competition fierce and the market increasingly fragmented.
Crohn’s disease
• Mirikizumab is the third IL-23 inhibitor launching for Crohn’s disease.
• Emerging therapies, including mirikizumab, will most likely be used in patients refractory to TNF-α inhibitors or who have failed multiple biological agents.
• There is significant commercial opportunity to treat patients refractory to TNF-α inhibitors given they fail to achieve treatment goals in a large proportion of patients.
Ulcerative colitis
• Mirikizumab is expected to launch at the same time as two other IL-23 inhibitors.
• Targeted therapies, such as mirikizumab, are typically used to treat moderate-to-severe disease.
• There is potential for approval in the pediatric population: expanded patient population, differentiation from other in-class competitors, filling the gap in limited targeted therapies for this population.

What gaps in treatment does mirikizumab fill?

Both Crohn’s disease and ulcerative colitis are characterized by intermittent disease courses, with acute flares followed by periods of remission. Patients risk hospitalization and the need for surgical intervention, in addition to experiencing poorer quality of life. Neither disease has a cure, so pharmacotherapy aims to induce remission of acute flairs, maintain remission (without corticosteroids) and improve quality of life. Treatment gaps that mirikizumab could help fill include sustainable long-term remission (many patients lose response to biologics) and therapies with alternative mechanisms of action for patients intolerant or resistant to TNF-α inhibitors.

What hurdles might it need to overcome to reach blockbuster status?

The later market entry of mirikizumab, after STELARA and other IL-23 inhibitors, for both Crohn’s disease and ulcerative colitis, will likely restrain its uptake. Regarding STELARA, gastroenterologists will have had 6-8 years of clinical experience prescribing it, and at least initially, new IL-23 inhibitors are unlikely to steal significant patient share and could be used primarily as later-line therapies. In addition, the launch of biosimilar ustekinumab, which is expected in 2023, could encroach on the use of all IL-23 inhibitors. Unless it shows significantly greater safety and efficacy, mirikizumab will be one of many therapeutic options in an increasingly crowded space.

$0.595B

expected sales in 2027

95%

probability of success for mirikizumab for ulcerative colitis in the United States.

“I feel that the data for mirikizumab are very good. Also, I would say that we still need overall data. I do not have a preference among all interleukin inhibitors; however, there is preference for ustekinumab because it is already in the clinical practice system.”