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.