Leflunomide in the treatment of psoriasis: results of a phase II open trial

Abstract

Background: Psoriasis is recognized as the most prevalent T-cell-mediated inflammatory disease in humans, with predominantly activated T-helper (Th) 1 cell effectors. Leflunomide exerts its anti-inflammatory activities by preventing the generation of proinflammatory Th1 effectors and promoting Th2 cell differentiation.

Objectives: To determine the safety and efficacy of leflunomide in patients with moderate to severe plaque-type psoriasis.

Methods: In an open-label phase II trial, eight patients with psoriasis received oral leflunomide 20 mg daily for 12 weeks. Patients were evaluated for improvement in psoriasis, quality of life, histological changes and toxicity.

Results: Antipsoriatic effects were obtained in all but two patients. A significant decrease was observed in the mean +/- SD Psoriasis Area and Severity Index score, from 20.08 +/- 6.85 before treatment to 12.51 +/- 11.83 after (P = 0.03). The antipsoriatic efficiency was confirmed histologically, with a significant mean +/- SD decrease in epidermal thickness, from 0.73 +/- 0.19 micro m before to 0.31 +/- 0.16 microm after (P = 0.01). The quality of life score showed an improvement, from 8.58 +/- 2.38 (mean +/- SD) before to 5.33 +/- 1.95 after (P = 0.02). The treatment was well tolerated; adverse reactions primarily consisted of transitory gastrointestinal events.

Conclusions: Our data suggest that leflunomide for plaque-type psoriasis is a safe and clinically effective option as monotherapy. However, double-blind, placebo-controlled studies are needed.