Trial of cyclosporin in corticosteroid-dependent chronic severe asthma. Treatment of steroid-dependent bronchial asthma with cyclosporin. Double-blind, placebo-controlled study of cyclosporin A as a corticosteroid-sparing agent in corticosteroid-dependent asthma.
The treatment of chronic severe asthma is unsatisfactory for many patients. In a randomised, double-blind, placebo-controlled, crossover trial we have tested whether cyclosporin, which is thought to act primarily by inhibition of T lymphocyte activation, improves lung function in corticosteroid-dependent asthmatics. After a 4-week run-in period, 33 patients with longstanding asthma (mean duration 27 years), and who had required continuous oral corticosteroids for a mean of 9.3 years, were randomised to receive either cyclosporin (initial dose 5 mg/kg per day) or placebo for 12 weeks, crossing over after a 2-week washout period. Mean baseline forced expiratory volume in 1 s (FEV1) was 60.1% of the predicted value. 2 patients failed to complete the protocol and 1 withdrew because of hypertrichosis. Cyclosporin therapy resulted in a mean increase above placebo of 12.0% in morning peak expiratory flow rate (PEFR; p less than 0.004) and 17.6% in FEV1 (p less than 0.001). The frequency of disease exacerbations requiring an increased prednisolone dose was reduced by 48% in patients on cyclosporin compared with placebo (p less than 0.02). Diurnal variation in PEFR decreased by a mean of 27.6% (p = 0.04). Cyclosporin for 12 weeks was well tolerated by this group of chronic asthmatics, in whom the mean whole-blood trough concentration was 152 micrograms/l. These findings provide further evidence of a role for activated T lymphocytes in the pathogenesis of asthma. Specific pharmacological targeting of this cell could form the basis of a novel approach to the treatment of asthma. The treatment of chronic severe asthma is unsatisfactory for many patients. The aim of the study was to determine the effects of treatment of steroid-dependent asthma with cyclosporin. We performed a double-blind, placebo-controlled, randomized, parallel group trial on the effect of cyclosporin on pulmonary function, asthma severity and tapering of prednisone in 34 steroid-dependent asthmatics (mean oral prednisone dose: 16 mg.day-1). The study consisted of: 1) baseline period (12 weeks); 2) experimental period divided into two parts: Part I (12 weeks) cyclosporin or placebo treatment; Part II (22 weeks) cyclosporin or placebo treatment and oral prednisone reduction; and 3) follow-up observation (8 weeks). Asthma symptoms score, pulmonary function tests (daily peak expiratory flow (PEF) and bi-weekly forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and maximal mid-expiratory flow (MEF50), biochemical profile and blood cyclosporin levels were monitored throughout the study. Following cyclosporin administration, a slight beneficial effect on some subjective parameters of asthma severity was observed. At the same time, no beneficial effect on pulmonary function was noted. The time trends analysis of mean daily prednisone doses between the treatment groups revealed a statistically significant difference indicating that, during prednisone reduction, cyclosporin seemed to be slightly more efficient than placebo in reducing the requirement for systemic corticosteroid, even though the steroid reduction was accompanied by slight impairment of some pulmonary function. However, there was no significant difference in the final dose reduction between the treatment groups. These data and the known toxicity of the drug suggest a limited place for cyclosporin treatment in steroid-dependent bronchial asthma. Patients with severe asthma who require long-term oral corticosteroid therapy are at risk of unwanted effects. Several immunosuppressive drugs have been assessed as corticosteroid-sparing agents in chronic asthma. We previously showed that cyclosporin A (CsA) administered for 12 wk improved lung function in corticosteroid-dependent patients. We have now investigated the corticosteroid-sparing properties of CsA over a 36-wk period. Following a 4-wk run-in period, 39 corticosteroid-dependent asthmatic patients were randomized to receive CsA (19 patients, initial doses 5 mg/kg/d) or matched placebo (20 patients) for 36 wk. Attempts were then made by a physician ignorant of the trial therapy to reduce their prednisolone dosages at 14-d intervals, provided that a patient's asthma remained stable or improved. Three patients receiving CsA had to be withdrawn from the study before they completed 12 wk of therapy. The remaining 16 patients achieved a statistically significant reduction in median daily prednisolone dosage of 62% (10 to 3.5 mg), compared with a decrease of 25% (10 to 7.5 mg) in the patients taking placebo (p = 0.043). This reduction was most pronounced during the last 12 wk of active therapy. In addition, morning peak expiratory flow rate (PEFR) improved significantly (mean 9.4%, SEM 3.0%) in the active-treatment group but not in the placebo group (p = 0.026 between groups). Predictable changes in renal function and blood pressure, and an increased incidence of hypertrichosis and paresthesia, were observed in the patients treated with CsA, but these did not necessitate withdrawal from the study, and were reversed during a 4-wk run-out period. Thus, low-dose CsA therapy, as compared with placebo, allowed a significant reduction in oral corticosteroid dosages in patients with severe asthma, and also improved lung function.
The changes with cyclosporin are small and of questionable clinical significance. Given the side effects of cyclosporin, the evidence available does not recommend routine use of this drug in the treatment of oral corticosteroid dependent asthma.