A Maintenance Study of Mirikizumab in Participants With Moderately to Severely Active Ulcerative Colitis

Clinical remission at week 40 is defined as achieving a 9-point modified Mayo score for rectal bleeding=0, stool frequency=0 or 1 with ≥ 1 point decrease from baseline, and endoscopy=0 or 1 (excluding friability). Stool Frequency Subscore, based on the participant's diary and scored from 0 (normal number of stools) to 3 (5 or more stools than normal); Rectal Bleeding Subscore, based on the participant's diary and scored from 0 (no blood) to 3 (blood only passed); Endoscopy Subscore, based on central reading of colonoscopy or sigmoidoscopy and scored from 0 (normal or inactive disease) to 3 (severe disease, spontaneous bleeding, ulceration).

Time frame: Week 40

Population: Modified Intention-to-treat population (mITT): All randomized participants who received at least one dose of study drug and who had the modified Mayo score measured correctly at baseline. Participants were analysed per their assigned treatment arm regardless of the treatment they actually received.

The Urgency NRS is a single participant reported item that measures the severity for the urgency (sudden or immediate need) to have a bowel movement in the past 24 hours using an 11-point NRS ranging from 0 (no urgency) to 10 (worst possible urgency). Higher scores indicate more severe urgency. Least square (LS) Mean was calculated using mixed model repeated measures (MMRM) model for post-baseline measures: The MMRM model includes treatment, baseline value, visit, interaction of baseline value-by-visit, interaction of treatment-by-visit, prior biologic or tofacitinib failure (yes/no), baseline corticosteroid use (yes/no), clinical remission status (yes/no) at AMAN Week 12, and region (North America/Europe/Other).

Time frame: Induction Baseline, Week 40

Population: Modified Intention-to-treat population (mITT): All randomized participants who received at least 1 dose of study drug and had a baseline and at least one post-baseline urgency NRS measurement. Participants were analysed per their assigned treatment arm regardless of the treatment they actually received.

Fecal calprotectin is an indicator of inflammation in the colon with higher levels indicative of higher levels of inflammation. Least square (LS) Mean was calculated using ANCOVA model for post-baseline measures: The ANCOVA model includes treatment, baseline value, prior biologic or tofacitinib failure (yes/no), corticosteroid use (yes/no) at AMAN baseline, region (North America/Europe/Other), Clinical Remission status (yes/no) at AMAN Week 12.

Time frame: Induction Baseline, Week 40

Population: Modified Intention-to-treat population (mITT): All randomized participants who received at least 1 dose of study drug and had a baseline and at least one post-baseline fecal calprotectin measurement. Participants were analysed per their assigned treatment arm regardless of the treatment they actually received.

The IBDQ is a 32-item participant-completed questionnaire that measures 4 aspects of subjects' lives: symptoms directly related to the primary bowel disturbance, systemic symptoms, emotional function, and social function. Responses are graded on a 7-point. Likert scale in which 7 denotes not a problem at all and 1 denotes a very severe problem. Scores range from 32 to 224; a higher score indicates a better quality of life. Least square (LS) Mean was calculated using analysis of covariance (ANCOVA) model for post-baseline measures: The ANCOVA model includes: treatment, baseline value, prior biologic or tofacitinib failure (yes/no), clinical remission status (yes/no) at AMAN Week 12, and region (North America/Europe/Other).

Time frame: Induction Baseline, Week 40

Population: Modified Intention-to-treat population (mITT): All randomized participants who received at least 1 dose of study drug and had a baseline and at least one post-baseline IBDQ measurement. Participants were analysed per their assigned treatment arm regardless of the treatment they actually received.

Percentage of participants hospitalized for UC. Only hospitalizations associated with an adverse event with \>=24 hours stay were recorded.

Time frame: Week 40

Population: Modified Intention-to-treat population (mITT): All randomized participants who received at least one dose of study drug. Participants were analysed per their assigned treatment arm regardless of the treatment they actually received.

Clinical response at week 40 is defined as a decrease in the 9-point modified Mayo score (MMS) \[rectal bleeding, stool frequency and the endoscopic findings\] inclusive of \>= 2 points and \>=30% from baseline with either a decrease of rectal bleeding subscore of \>=1 or rectal bleeding subscore of 0 or 1.The MMS is a composite score of ulcerative colitis disease activity calculated as the sum of three subscores: Stool frequency subscore, based on the participant's diary and scored from 0 (normal number of stools) to 3 (5 or more stools than normal); Rectal bleeding subscore, based on the participant's diary and scored from 0 (no blood seen) to 3 (blood alone passed); Endoscopy subscore, based on colonoscopy or sigmoidoscopy and scored from 0 (normal or inactive disease) to 3 (severe disease, spontaneous bleeding,ulceration).

Time frame: Week 40

Population: Modified Intention-to-treat population (mITT): All randomized participants who received at least one dose of study drug and who had the modified Mayo score measured correctly at baseline. Participants were analysed per their assigned treatment arm regardless of the treatment they actually received.

Endoscopic remission at week 40 is defined as achieving a Mayo endoscopic subscore of 0 or 1 (excluding friability) at Week 40. Endoscopy subscore is based on colonoscopy or sigmoidoscopy and scored from 0 (normal or inactive disease) to 3 (severe disease, spontaneous bleeding, ulceration).

Time frame: Week 40

Population: Modified Intention-to-treat population (mITT): All randomized participants who received at least one dose of study drug and who had the modified Mayo score measured correctly at baseline. Participants were analysed per their assigned treatment arm regardless of the treatment they actually received.

Endoscopic response at week 40 is defined as achieving at least a 1 point decrease from baseline in the Mayo endoscopic subscore.

Time frame: Week 40

Population: Modified Intention-to-treat population (mITT): All randomized participants who received at least one dose of study drug and who had the modified Mayo score measured correctly at baseline. Participants were analysed per their assigned treatment arm regardless of the treatment they actually received.

Symptomatic remission at week 40 is defined as a Mayo score for rectal bleeding=0, stool frequency=0 or 1 with ≥ 1 point decrease from baseline. Stool frequency subscore, based on the participant's diary and scored from 0 (normal number of stools) to 3 (5 or more stools than normal). Rectal bleeding subscore, based on the participant's diary and scored from 0 (no blood seen) to 3 (blood alone passed).

Time frame: Week 40

Population: Modified Intention-to-treat population (mITT): All randomized participants who received at least one dose of study drug and who had the modified Mayo score measured correctly at baseline. Participants were analysed per their assigned treatment arm regardless of the treatment they actually received.

Histologic remission was assessed using the Geboes histologic scoring system developed for assessment of histologic disease activity in ulcerative colitis. Remission was defined as Geboes histological subscore of 0 for grades: 2b (lamina propria neutrophils), and 3 (neutrophils in epithelium), and 4 (crypt destruction), and 5 (erosion or ulceration).

Time frame: Week 40

Population: Modified Intention-to-treat population (mITT): All randomized participants who received at least one dose of study drug and who had the modified Mayo score measured correctly at baseline. Participants were analysed per their assigned treatment arm regardless of the treatment they actually received.

Clearance of mirikizumab was evaluated.

Time frame: Predose: Weeks 0, 4, 12, 24 and 40

Population: All randomized participants who received at least one dose of study drug subcutaneously (both induction responders and nonresponders) and had evaluable PK data.