Use of intermittent, intravenous cyclophosphamide for idiopathic pulmonary fibrosis

To determine the safety and efficacy of intravenous cyclophosphamide for patients with idiopathic pulmonary fibrosis.

Nonrandomized, open-labeled study of efficacy in symptomatic patients.

Patients were treated as outpatients in a referral clinic.

All patients had idiopathic pulmonary fibrosis with symptoms of dyspnea on exertion. Patients had either worsening disease or contraindication to corticosteroids.

Thirty-three patients were treated with intravenous cyclophosphamide every two weeks. Initial dosage was 500 mg, and the dose was escalated provided the total white blood cell count remained > 3,000 cells per cubic millimeter. The maximum dose administered was 1,000 to 1,800 mg of cyclophosphamide. Corticosteroid therapy was tapered as tolerated by the patient.

Patients were treated for at least six months or until death. For the 33 patients, 18-month probability of survival was > 50 percent. For those patients surviving six months, there was a significant rise in the vital capacity (from 1.6 +/- .61 L [mean +/- SD] to 1.8 +/- .52 L, p < 0.01) which persisted for at least 18 months of treatment. This was associated with a significant fall in the average prednisone dosage from 32 +/- 13.0 mg/day to 4 +/- 10.4 mg/day (p < 0.01) by 12 months. Only one patient required hospitalization for possible drug-related toxic reaction.

Intermittent, intravenous cyclophosphamide therapy was associated with improved pulmonary function and reduced corticosteroid dosage in patients with idiopathic pulmonary fibrosis who survived at least six months after institution of therapy.