This is an open-label (both \[participants and investigator\] know what treatment participants will receive) and multicenter study. The study is divided into 2 parts: Part 1: pharmacokinetics portion (Week 0 to Week 14); Part 2: study extension (Week 14 to Week 114). The focus of this study is to evaluate the pharmacokinetics and safety of golimumab. Additionally the efficacy of short-term therapy with golimumab will be evaluated. Participants in clinical response at Week 6 will continue to receive open label golimumab maintenance therapy and will enter the study extension at Week 14. Participants who are not in clinical response at Week 6 will be withdrawn from further treatment with golimumab. At Week 114, participants who, in the opinion of the investigator, may benefit from continued treatment will be eligible to continue to receive golimumab every 4 weeks until marketing authorization is obtained in the treatment of pediatric UC in that country, or until a decision has been made not to pursue an indication in pediatric UC. Approximately 30 participants will be enrolled in this study. The total duration of study participation for a participant will be approximately 126 weeks or longer.
