 Eligible participants that choose to enroll in the extension study will have an additional treatment period of up to 192 weeks and will be monitored for an additional 20 weeks in the follow-up period. Each participant will receive tildrakizumab 200 mg or tildrakizumab 100 mg every 12 weeks up to study Week 244 according to their treatment assignment at the conclusion of Part 3 of the base study. 