An experimental ointment formulation of pimecrolimus is effective in psoriasis without occlusion

Pimecrolimus (Elidel, SDZ ASM 981), a new macrolactam ascomycin derivative, was highly effective in treating plaque-type psoriasis when applied under Finn-chamber occlusion. A two-centre, randomized, double-blind, vehicle- and positive-controlled within-patient study was therefore conducted in 23 adult psoriasis patients. Pimecrolimus 1% was applied, twice daily, in an experimental ointment formulation, along with the corresponding vehicle, 0.005% calcipotriol ointment and 0.05% clobetasol-17-propionate ointment to test sites without occlusion for 21 days. Erythema, induration and scaling (score: 0 [absent] to 4 [severe]) were evaluated. The total sign score was defined as the sum of the erythema, induration and scaling scores (range 0-12). Pimecrolimus 1% ointment was significantly (p = 0.03) more effective than the corresponding vehicle, with an improvement in total sign score of 51.4% compared with 36.7% for the corresponding vehicle. Improvements with calcipotriol and clobetasol-17-propionate were 71.5% and 88.3%, respectively. No local or systemic drug-related side effects were observed in the study. We conclude that pimecrolimus 1% in the experimental ointment formulation was significantly more effective than its corresponding vehicle, but less effective than calcipotriol and clobetasol ointment. This is the first study reporting a significant therapeutic effect of pimecrolimus in an ointment formulation applied without occlusion to psoriatic plaques.