Study participants will be divided into two groups. One group will take 100 milligrams of Leflunomide once a day for 3 days and then 20 milligrams once a day for 6 months. The other group will take a placebo-a pill that looks like the Leflunomide pill but does not contain the medicine. All patients in both groups will also take prednisone. Patients will have follow-up examinations at weeks 1, 4, 8, 12, 16, and 24 (6 months) of the study. Each follow-up visit will include a repeat of the screening exams and an evaluation of side effects or discomfort from the medicine. Those who do well and want to continue their assigned treatment after 6 months can continue that treatment for another 6 months and will have follow-up exams at months 9 and 12.