Ontamalimab

Remission: a composite score of participant reported symptoms using daily e-diary and centrally read endoscopy as follows: stool frequency sub-score 0 or 1 with at least a 1-point change from induction study baseline; and rectal bleeding sub-score of 0; and endoscopic sub-score 0 or 1 (modified, excludes friability). The composite score was a recommended measure consisted of Mayo score without the Physician global assessment (PGA) sub-score and ranges from 0-9 points. The Mayo score was a measure of UC disease activity ranged from 0-12 points and consisted of 4 sub-scores, each graded from 0-3 with higher scores indicating more severe disease. Sub-scores were rectal bleeding (range: 0-3, where 0= no blood \& 3=blood alone passes), stool frequency (range: 0-3, where 0= normal number of stools and 3=at least 5 stools more than normal), PGA sub-score (range: 0-3- higher score= severe disease), and an endoscopic sub-score (range: 0-3, where 0= normal/inactive disease; 3= severe disease).

An adverse event (AE) was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. Treatment-emergent AEs (TEAEs) were defined as AEs with start dates or worsening dates at the time of or following the first exposure to investigational product.

Serious infections were defined as any infections that were life-threatening or those requiring hospitalization or intravenous antibiotics based on the investigator's assessment.

Clinical laboratory assessments included hematology, serum chemistry and urinalysis. Any notable changes in the clinical laboratory value over time based on the investigator interpretation were reported.

ECG included heart rhythm, heart rate, QRS intervals, QT intervals, RR intervals and corrected QT (QTc) intervals parameters measurement. Any discernible changes in the ECG value over time based on investigator interpretation were reported.

Vital sign assessments included blood pressure, pulse, respiratory rate, and temperature. Any discernible changes in vital signs over time per investigator interpretation were reported.

An adverse event (AE) was defined as any untoward medical occurrence in a clinical investigation participant who was administered a product or medical device; the event did not need to necessarily have a causal relationship with the treatment or usage. A serious adverse event (SAE) was any untoward medical occurrence at any dose that resulted in death, was life threatening (immediate risk of death), required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, resulted in congenital anomaly/birth defect. Number of participants with TEAEs, STEAEs, and those withdrew from treatment due to TEAEs were reported.

Clinical remission was defined as a Total Mayo Score of less than or equal (\<=) 2 points with no individual subscore exceeding 1 point and rectal bleed subscore of 0 or 1. The Mayo Score is a tool designed to measure disease activity for ulcerative colitis (UC). Scoring ranges from 0 to 12 points and consists of 4 subscores, each graded 0 to 3 with higher score indicating more severe disease activity. Endoscopic readings from the local and the central reader were considered for analysis. The central reading was used as the primary analysis and the local readings were used for the sensitivity analyses.

AEs included adverse drug reactions, illnesses with onset during the study, exacerbation of previous illnesses, clinically significant changes in physical examination findings and abnormal objective test findings (ECG, laboratory). An SAE was defined as any AE at any dose that resulted in death; was life threatening (immediate risk of death); required in-subject hospitalization or prolongation of existing hospitalization; resulted in a persistent or significant disability/incapacity (substantial disruption of the ability to conduct normal life functions); or resulted in congenital anomaly/birth defect.

Crohn's Disease Activity Index (CDAI) is a number which consists of information collected from a 7-day diary from the participants regarding symptoms. Remission is considered a score of 150 or less. Active disease is considered 200 or greater. A response to therapy is considered a decline in CDAI score of 70-points from baseline. CDAI response rate at week 8 and week 12 was measured between the investigational product group and the placebo group.