BACKGROUND: Previous clinical studies have demonstrated that injectable gold salts and the oral gold compound, auranofin, possess significant steroid-sparing effects in the treatment of asthma. OBJECTIVES: The objectives of this investigation were to determine whether auranofin could reduce oral corticosteroid requirements and to evaluate the safety of auranofin in the treatment of chronic corticosteroid-dependent asthma. METHODS: Patients with asthma were eligible if they required at least 10 mg of prednisone per day for control and prevention of asthma exacerbations. Two hundred seventy-nine patients with chronic corticosteroid-dependent asthma (requiring > or = 10 mg/day) were randomized to receive auranofin, 3 mg twice daily, or placebo during an 8-month clinical trial, which was divided into three phases including: a 4-week baseline period (phase I), a 6-month double-blind treatment and steroid reduction period (phase II), and a 4-week posttreatment observation period during which steroid and auranofin doses or placebo doses were maintained at levels achieved by the end of phase II (phase III). The primary efficacy variable was "therapeutic success" or reduction of daily corticosteroid use by 50% or more. RESULTS: The proportion of patients in the auranofin group achieving therapeutic success (41%) was significantly higher than that in the placebo group (27%) (p = 0.01). This effect was greatest in patients requiring 10 to 19 mg of oral prednisone per day at baseline (p < 0.001). In all treated patients, including those who did and did not complete the trial, significant reduction (> or = 50% of baseline) in oral corticosteroid dosage was achieved in the auranofin group (60%) compared with the placebo group (32%) (p < 0.001). There were no significant differences between treatment groups in symptoms, concomitant medication use, or lung function. Mean serum total IgE levels decreased significantly from baseline in the auranofin group (-44.63 IU/ml) compared with the placebo group (p = 0.001). Gastrointestinal and cutaneous adverse events were greater in the auranofin group. CONCLUSIONS: Auranofin demonstrated a steroid-sparing effect without concomitant worsening of symptoms or lung function and appeared to be more effective in patients dependent on 10 to 19 mg of prednisone per day. Therefore this study has demonstrated that auranofin is useful as a steroid-sparing agent in the treatment of chronic corticosteroid-dependent asthma.