To determine the lowest effective starting dose and residual benefit of cyclosporine A (CSA) in patients with rheumatoid arthritis (RA) refractory to other agents.
In a double blind (masked observer), controlled, multicenter study, patients with RA started CSA 0 (placebo; n = 61), 1.5 (n = 89), or 2.5 (n = 94) mg/kg/day in a 21 week study that permitted dose escalation after 8 weeks, 1 week tapering of dose at 16 weeks, and post-therapy observation for 4 weeks.
Patients with RA taking CSA 2.5 mg/kg/day fared better than those in the placebo or CSA 1.5 mg/kg/day groups in Patient Global Assessment, Examiner Global Assessment, Pain/Tender Joint Count and Index, Swollen Joint Count, and the "Ability at this moment" part of a modified Health Assessment Questionnaire. There was no difference in response between CSA 1.5 mg/kg/day and placebo groups. In the CSA 2.5 mg/kg/day group: improvement occurred between 8 and 12 weeks of therapy; average CSA dose escalation resulted in CSA 2.85 mg/kg/day by Week 16; benefit was not maintained during post-therapy observation and 7 patients discontinued the study because of an adverse event. Adverse events were common in all groups and included gastrointestinal discomfort, hypertension, and increased creatinine. Adverse events remitted with adjustment of dose or after washout in most patients.
In RA, treatment of patients with CSA 2.5 mg/kg/day, but not 1.5 mg/kg/day, resulted in improvement of 4 of 5 primary efficacy variables when compared to placebo. Adverse events were mostly manageable. CSA was an effective therapy for patients with RA who had failed at least one second line agent.