Includes modifications to the Schedule of Activities and Biomarker sections to provide clarity; added new Section 8.1.1 and language throughout protocol regarding central read versus local read of endoscopy; clarified corticosteroid use as a rescue medication; and added discontinuation criteria and study stopping rules to align with recent FDA communications

This country-specific amendment applies to all subjects enrolled in Japan. The purpose of this Amendment is to incorporate local regulatory requirements for Japanese sites.

Adding “or age of majority” to inclusion criterion to align with local regulatory requirements for South Korean sites

This country-specific amendment applies to all subjects enrolled in the Czech Republic. The purpose of this Amendment is to adjust the maximum age of subjects from 80 to 70 years of age, and to align Section 8.2.5 Pregnancy with local regulatory requirements for Czech Republic sites.

This country-specific amendment applies to all subjects enrolled in Germany. Modifications include: • Exclusion Criterion 7)a) has been revised to exclude prisoners or subjects who are involuntarily incarcerated from trial participation. • Section 7.1.1 (Post-Study Treatment Follow-up) has been revised to state that participants who discontinue study treatment will be followed for 28 days or longer, as required, and in line with Section 8.2.3. • Section 8.2.1 and APPENDIX 3 have been revised to state that serious adverse events (AEs) need to be reported ‘immediately’ to Sponsor or designee but no later than 24 hours after awareness of the event. • Section 8.2.5 (Pregnancy) has been revised to state that study drug treatment must be discontinued immediately in case of pregnancy and that the pregnancy must be reported within 24 hours of awareness of the pregnancy. • APPENDIX 3 has been revised to state that nonserious AEs that cause interruption or discontinuation of study treatment must be followed to resolution or stabilization.

Includes the following modifications: • add a 52-week open-label extension period to provide the option of additional treatment to subjects deriving clinical benefit at Week 52; • modify the type and/or frequency of various study assessments to improve subject safety and minimize subject burden; provide additional detail for each of the study periods, including clear guidance for management of Week 12 responders and nonresponders in the maintenance period and additional hepatitis B Virus (HBV) and hepatitis C Virus (HCV) screening and monitoring information; • modify several inclusion and exclusion criteria to increase subject eligibility, and add specific randomization criteria to aid in final determination of eligibility; • incorporate several elements from the South Korea and Germany specific v2.0 amendments regarding age of majority, and follow-up after discontinuation and adverse events; • revise or clarify the definitions of key study terms and endpoints; add several exploratory endpoints; • revise or clarify the following study elements: prohibited and restricted treatments; use and tapering of corticosteroids during all study periods; criteria defining treatment failure; criteria leading to discontinuation; and criteria defining inadequate response, loss of response, and intolerance to previous biologic therapy; • clarify sample size calculation, planned exploratory analyses, and other analyses including quality of life and healthcare resource utilization; • remove or modify several contraception requirements to reflect recent toxicology data consistent with these changes; • implement other revisions including modification of text regarding safety reporting requirements; and addition of several new appendices to evaluate UC disease activity, patient-reported outcomes, and healthcare resource utilization.