Patients who meet the inclusion and exclusion criteria will be randomized to be treated with either placebo or pirfenidone at the current approved dosage for idiopathic pulmonary fibrosis at a 2:1 pirfenidone to placebo ratio. Patients treated with pirfenidone will be titrated using the following schedule:
One 267 mg capsules three times a day for two weeks. Two 267 mg capsules three times a day for two weeks Three 267 mg capsules three times a day thereafter Patients will be instructed to take all doses of medication with food. Dosage will be titrated on an individual basis depending on patient tolerance of medication.
Those randomized to placebo will receive the same schedule using placebo tablets.
Block randomization will be done at each site. Liver function tests will be evaluated as listed above. If the patient has an abnormal liver function test, then the dose will be adjusted per the company's protocol for commercial drug.