 Published evidence suggests that less than 20 of patients with IPF respond to corticosteroids prednisone. In patients that fail steroids, immunosuppressant drugs such as azathioprine or cyclophosphamide are used. An international consensus statement recommends both steroids and azathioprine or cyclophosphamide from the onset of treatment. Unfortunately a large number of trials have shown little or no effect of these drugs on the progression of disease. There are currently no FDA approved drugs for the treatment of IPF. 