Long-Term Efficacy and Safety Evaluation of Mirikizumab in Patients with Moderately to Severely Active Ulcerative Colitis: A Phase 3, Multicenter, Open-Label Extension Study

The primary objective of this Phase 3, multicenter, open-label extension study is to evaluate the long-term **efficacy** and **safety** of **mirikizumab** in patients with moderately to severely active **ulcerative colitis**. This study aims to determine if sustained treatment with mirikizumab can provide ongoing therapeutic benefits and maintain disease control in this patient population. The clinical relevance of this objective lies in addressing the chronic nature of ulcerative colitis, which requires effective long-term management strategies to improve patient outcomes and quality of life.

The clinical trial involves a total of **732 participants** diagnosed with **ulcerative colitis**. The study population includes both male and female subjects, with an age range that spans from 18 to 65 years. Participants were selected from previous studies, specifically Study AMAC (NCT02589665) or AMBG (NCT03524092), provided they had received at least one administration of the study drug and had not experienced early termination of the study drug. The trial includes a vulnerable population, indicating that special considerations are in place to ensure their safety and well-being. Participants are required to adhere to specific lifestyle considerations, such as contraception requirements for female participants. The selection criteria ensure a diverse and representative sample of individuals affected by ulcerative colitis, allowing for comprehensive evaluation of the long-term effects of the study medication, mirikizumab.

The clinical trial is designed to evaluate the long-term efficacy and safety of **mirikizumab** in patients with moderately to severely active **ulcerative colitis**. This is a Phase 3, multicenter, open-label extension study. The trial is not categorized as low intervention and is conducted to assess the long-term safety and efficacy of an authorized investigational medicinal product. The study commenced recruitment on October 4, 2018, and is estimated to conclude by July 15, 2025. Participants eligible for this study are those who have previously participated in Study AMAC (NCT02589665) or AMBG (NCT03524092) and have received at least one administration of the study drug without early termination.

The trial involves a series of study visits, beginning with an inclusion (screening) visit to confirm eligibility based on the principal inclusion criteria. Participants will undergo regular follow-up visits to monitor their response to the treatment and assess any adverse effects. The primary endpoint is the percentage of participants achieving clinical remission, as determined by the modified Mayo Score. Secondary endpoints include the percentage of participants in endoscopic remission, hospitalization rates due to ulcerative colitis, rates of ulcerative colitis-related surgeries, and changes in IBDQ scores over time.

The expected duration of participant involvement is aligned with the overall trial duration, extending until the estimated end date in 2025. However, conditions such as non-compliance with the study protocol, withdrawal of consent, or adverse events may lead to early termination from the study. The investigational product, **mirikizumab**, is administered as a solution for injection, and participants are required to adhere to specific contraception requirements if applicable. The study aims to provide comprehensive data on the long-term use of **mirikizumab** in managing **ulcerative colitis**.

The clinical trial involves the administration of **Mirikizumab**, a monoclonal antibody specifically targeting the p19 subunit of the IL-23 cytokine. This experimental medication is provided in the form of a **solution for injection**. The pharmaceutical form is consistent across all administrations, ensuring uniformity in the delivery method. The active substance, **mirikizumab**, is a protein-based therapeutic agent developed by Eli Lilly and Company Limited. The medication is not formulated for pediatric use and is not classified as an orphan drug. The dosing regimen specifies a maximum treatment period of one unit of time, with no specified maximum daily or total dose amount, indicating flexibility in dosing based on clinical judgment and patient response.

In this study, no non-experimental treatments such as standard-of-care therapy, placebo, or comparator treatments are explicitly mentioned. The focus remains solely on evaluating the long-term efficacy and safety of **mirikizumab** in patients with moderately to severely active ulcerative colitis. The trial does not include any additional devices for drug administration, and the solution for injection is the sole route of administration. Participant compliance with the dosing schedule is monitored to ensure adherence to the treatment protocol, although specific compliance monitoring methods are not detailed in the provided data.

The efficacy of the clinical trial evaluating **Mirikizumab** in patients with moderately to severely active ulcerative colitis will be assessed using both primary and secondary endpoints. The primary endpoint is the percentage of participants achieving clinical remission, which is determined based on the modified Mayo Score (MMS). Secondary endpoints include the percentage of participants in endoscopic remission, assessed using the Mayo Endoscopic Score (ES), the percentage of participants hospitalized due to ulcerative colitis over time, the percentage of participants undergoing ulcerative colitis surgeries over time, and the Inflammatory Bowel Disease Questionnaire (IBDQ) scores over time.