This study will consist of 3 periods: first, a double-blind period (weeks 0-12) in which subjects will be randomized to etanercept 50 mg twice weekly or placebo; second, an open-label period (weeks 12-24) in which subjects who were randomized to placebo treatment, who have not achieved a complete remission, will be rolled over to use etanercept at 50 mg twice weekly. Subjects who previously received etanercept during weeks 0-12, who have not achieved a complete remission, will be continued on etanercept at a lower dosage of 25 mg twice weekly for weeks 12-24; third, an 8 week follow-up period for all subjects.