DURATION OF REMISSION DURING MAINTENANCE CYCLOSPORINE THERAPY FOR PSORIASIS - RELATIONSHIP TO MAINTENANCE DOSE AND DEGREE OF IMPROVEMENT DURING INITIAL THERAPY

Background: Cyclosporine therapy is highly effective in the treatment of psoriasis. To minimize side effects, the lowest effective dosage for maintenance therapy should be sought. Methods: We selected 61 patients who had achieved clearing or near-clearing of psoriasis during an induction phase of cyclosporine therapy. We then randomly assigned them in a double-blind fashion to receive one of two dosages of cyclosporine (1.5 or 3 mg/kg per day) or placebo for maintenance treatment. For each patient, the time to relapse was the time from the start of maintenance therapy until the patient showed a two-point worsening of psoriasis on a seven-point scale, up to a maximum of 4 months, when the study ended. Results: Sixty patients completed the maintenance study. The mean time to relapse was significantly longer in the 3-mg/kg group (12+/-1 weeks) than in the 1.5-mg/kg group (9+/-1 weeks; P=.04) and the placebo group (7+/-1 weeks; P=.002); the latter two groups were not significantly different (P=.3). When the study ended, 57% of the 3-mg/kg group had not relapsed, compared with 21% and 5% of the 1.5-mg/kg and placebo groups, respectively. The following factors were associated with longer remissions: less psoriasis at the start of maintenance dosing (r=.40, P=.002); lower dosage of cyclosporine to achieve clearing or near-clearing during induction (r=-.30, P=.02); higher maintenance dosing (r=.38, P=.004); and smaller differences between the induction and maintenance dosages (r=-.41, P=.002). Patients' laboratory values improved compared with those at induction, and no patient experienced important clinical side effects during maintenance dosing. Conclusions: After clearing or near-clearing is achieved in patients with severe psoriasis, 3 mg/kg per day is a reasonable dosage to choose for maintenance. Patients who are more responsive to cyclosporine (as measured by greater clearing of psoriasis at lower induction dosages) tend to have longer remissions.