Abatacept for the Treatment of Relapsing, Non-Severe, Granulomatosis With Polyangiitis (Wegener's)

Multi-center, randomized, double-blind, placebo-controlled trial to evaluate the efficacy of abatacept to achieve sustained glucocorticoid-free remission in patients with relapsing non-severe GPA. Patients who enter the trial will be maintained on a stable dose of their maintenance immunosuppressive agent which may include methotrexate (MTX), azathioprine (AZA), or mycophenolate (MA) and will undergo a blinded randomization to receive abatacept or placebo. Patients will additionally receive prednisone 30 mg daily that will then be tapered to zero using a standardized tapering schedule. If an enrolled patient experiences a non-severe relapse or non-severe disease worsening though common closing, or if they have not achieved remission by month 6, they will have the option of entering an open-label trial period whereby they would receive abatacept in conjunction with their maintenance immunosuppressive and a standardized glucocorticoid taper. Patients with a severe disease relapse or severe disease worsening will have met criteria for early termination criteria and be removed from active study treatment. Patients will remain on study until reaching criteria for early termination or until common closing, 12 months after randomization of the final patient. After common closing or early termination, patients will be treated with best medical judgment and will undergo a post-treatment safety visit 3 months after coming off of study treatment.