Infliximab and Intravenous Immunoglobulin Therapy in Treating Patients With Steroid-Refractory Pneumonitis

PRIMARY OBJECTIVE: I. To assess pneumonitis response to additional immunosuppression (infliximab or intravenous immunoglobulin therapy \[IVIG\]) in patients with steroid-refractory pneumonitis at 28-days. SECONDARY OBJECTIVES: I. To assess functional parameters of steroid-refractory pneumonitis at day 1, 14-days and 28-days after day 1 of receipt of additional immunosuppression (infliximab or IVIG). II. To assess radiologic parameters of steroid-refractory pneumonitis at day 1, 14-days and 28-days after day 1 of receipt of additional immunosuppression (infliximab or IVIG). III. To assess patient-reported outcomes of steroid-refractory pneumonitis at day 1, 14-days and 28-days after day 1 of receipt of additional immunosuppression (infliximab or IVIG). IV. To assess death after additional immunosuppression. V. To assess the rate of infections in the 28-day period after additional immunosuppression. EXPLORATORY OBJECTIVES: I. To examine lung tissue, bronchoalveolar lavage (BAL) and serial blood samples in patients who develop steroid-refractory pneumonitis. II. To examine associations between BAL phenotypes and pneumonitis response, functional and radiologic parameters of pneumonitis. III. To evaluate associations between pneumonitis and autoantibodies, T-cell expansion, and baseline cytokines in the blood. OUTLINE: Patients are randomized to 1 of 2 arms. ARM A: Patients receive infliximab intravenously (IV) on day 1 followed by prednisone taper IV or orally (PO) for 4-6 weeks in the absence of disease progression or unacceptable toxicity. Patients may receive an additional dose of infliximab IV on day 14 at the discretion of the treating physician. ARM B: Patients receive intravenous immunoglobulin therapy IV over 2-5 days per institutional guidelines followed by prednisone taper IV or PO for 4-6 weeks in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 28, 42 and 56 days.