This trial is extension part of the P04280 (placebo-controlled, double-blind, randomized study of chronic treatment with infliximab in approximately 140 patients, NCT00202852). This study will be conducted at 6 study centers in South Korea. After completion of the last follow-up visit at Week 30 and code break in main double-blind trial, subjects randomized to the placebo group and those who were treated with an infliximab-containing regimen who maintained clinical response at the time of study completion will be provided with open-label infliximab for treatment of their conditions and additional safety data will be collected.