Patients completing the 1st phase and those discontinued due to lack of efficacy after week 6 will continue into the 2nd phase to complete a total of 52 weeks. The 2nd open-phase will demonstrate the sustained efficacy, safety, and tolerability of infliximab along 52 weeks (weeks 12, 18, 24, 30, 36, 42 and 48). Efficacy analysis will focus on the change of the primary efficacy measurement and secondary measures on each scheduled visits- and any discontinuation visit compared to week 0.