Cyclophosphamide versus placebo in scleroderma lung disease

Area of Science:

• Pulmonary Medicine
• Rheumatology
• Clinical Pharmacology

Background:

• Scleroderma-related interstitial lung disease (ILD) is a significant cause of morbidity and mortality.
• Active alveolitis and impaired lung function characterize this condition.
• Limited effective treatments exist for scleroderma-related ILD.

Purpose of the Study:

• To evaluate the efficacy of oral cyclophosphamide in improving lung function and health-related symptoms in patients with scleroderma-related ILD.
• To assess the long-term effects of cyclophosphamide treatment on pulmonary function.
• To determine the safety profile of oral cyclophosphamide in this patient population.

Main Methods:

• A double-blind, randomized, placebo-controlled trial was conducted across 13 US clinical centers.
• 158 patients with scleroderma, restrictive lung physiology, dyspnea, and evidence of inflammatory ILD were enrolled.
• Patients received oral cyclophosphamide (up to 2 mg/kg/day) or placebo for one year, with follow-up to 24 months. Pulmonary function was assessed quarterly.

Main Results:

• 145 patients completed at least six months of treatment.
• A statistically significant improvement in forced vital capacity (FVC) was observed in the cyclophosphamide group compared to placebo at 12 months (mean difference 2.53%).
• Improvements in FVC were maintained at 24 months. Adverse events were more frequent with cyclophosphamide, but serious adverse events did not differ significantly between groups.

Conclusions:

• One year of oral cyclophosphamide provides a modest but significant benefit for lung function and symptoms in patients with symptomatic scleroderma-related ILD.
• The beneficial effects on lung function persist through 24 months.
• Oral cyclophosphamide demonstrates a favorable risk-benefit profile for managing scleroderma-related ILD.