- Use of any of the following within 28 days of enrollment: investigational therapy, cytotoxic/immunosuppressive agents other than corticosteroids (including but not limited to azathioprine, cyclosphosphamide, methotrexate, cyclosporine); cytokine modulators (including but not limited to etanercept and infliximab); therapies targeted to treat pulmonary fibrosis (including but not limited to D-penicillamine, colchicine, interferon gamma-1b, bosentan, N-acetylcysteine