Abatacept in Treating Adults With Mild Relapsing Wegener's Granulomatosis

Current standard treatment for WG involves various medications and is based on disease severity. Unfortunately, more than 50% of people experience a relapse after remission, placing them at risk for additional organ damage and medication toxicity. To prevent this, safer and more effective treatments for mild relapses are needed. Several studies have shown that activated T cells, a type of white blood cell important in regulating immune responses, play a role in WG. Abatacept, an immunoglobulin-based medication approved by the FDA to treat rheumatoid arthritis, acts by preventing T-cell activation and may be useful in treating mild relapses of WG. The purpose of this study is to determine the safety and effectiveness of abatacept in treating adults with mild relapsing WG. Participants will receive abatacept intravenously at study visits on Days 1, 15, and 29, and then once a month thereafter. A participant's abatacept dose is based on body weight and will remain the same throughout the study. Participants who are receiving maintenance immunosuppressive medications consisting of methotrexate, azathioprine, or mycophenolate mofetil at the time of enrollment will remain on these medications without dosage increase or reduction. Eligible participants may be on up to prednisone 15mg daily at the time of relapse. Following the development of relapse, participants may be treated with up to prednisone 30mg daily if necessary, but must to be back to the same dose that they had been on prior to relapse by Month 2. All study visits include medication review, physical exam, blood and urine collection, and questionnaires. A chest x-ray, computed tomography (CT) scan of the chest and sinuses, and lung function testing will occur at some study visits. Participants whose symptoms did not improved by Month 2 will be taken off abatacept. Any participants undergoing early termination or, after common closing, will undergo three follow-up study visits at 1, 3, and 6 months after the end of treatment.