Cyclophosphamide may prop up lung function in scleroderma.(Pulmonary Medicine)

The immunosuppressant drug cyclophosphamide may attenuate the decline in lung function that comes with scleroderma, according to a recent multicenter trial.

The study suggests that differences in lung function as small as 2%-3% may brighten the quality of life among scleroderma patients. Loss of vital capacity in scleroderma "shortens life and increases morbidity," Philip Clements, M.D., of the University of California, Los Angeles, a coauthor of the trial, said in an interview.

Although lung function did not improve in patients taking cyclophosphamide (Cytoxan) in the trial, it deteriorated less than in those who took placebo, he said.

About 60%-70% of patients with scleroderma die within 10 years. Most develop interstitial lung disease (ILD). About 15% of patients will go on to severe lung disease with forced vital capacity (FVC) of less than 50% of normal.

No cure exists for scleroderma and its associated lung disease. But for more than a decade, researchers have investigated a variety of therapies to slow its inflammatory cascade. The new trial, known as the Scleroderma Lung Study, is the first large, randomized, controlled, double-blind trial to investigate the influence of cyclophosphamide on lung function in scleroderma patients with ILD. The goal is to see whether cyclophosphamide is effective early in the course of ILD, before the disease does irreversible damage.

Dr. Clements and his colleagues enrolled 156 patients with scleroderma of less than 7 years' duration, who had shortness of breath, the appearance of "ground glass" on lung CT scans, and FVC less than 85% of predicted normal.

The researchers randomized patients to receive either cyclophosphamide or placebo (1 mg/kg per day initially, followed by increases of 25 mg every 4 weeks until the daily dose reached 2 mg/kg per day or was limited by toxicity). On average, the subjects were 48 years old and had had scleroderma for 3 years; 71% were female. Their FVC was 68%, total lung capacity was 70%, and diffusing capacity was 47%.