Interleukin 10 treatment of psoriasis - Clinical results of a phase 2 trial

Objective: To determine the safety and clinical effects of interleukin 10 ( IL-10) treatment of psoriasis. Design and Methods: In an open-label phase 2 trial, 10 patients with psoria sis subcutaneously received recombinant human IL-10 over a 7-week period in a dosage of 8 mu g/kg daily (n=5) or 20 mu g/kg 3 times per week (n=5). Pa tients were followed up for an additional 5 weeks. Results: The treatment was well tolerated. Antipsoriatic effects were found in all but 1 patient. A significant decrease of the psoriasis area and sev erity index by 55.3% +/- 11.5% (mean +/- SEM) was observed (P<.02). The ant ipsoriatic efficiency was confirmed by histological examination. Heterogene ity in the effectiveness was found among the patients, but seems to be inde pendent of the dosage regimen. However, a tendency to a better response was found in the patients who received 20-mu g/kg IL-10 3 times per week. Decr easing response in the delayed-type hyper-sensitivity reaction against reca ll antigens indicated immunosuppressive effects. Moderate effects on hemato poietic cells were observed. Conclusions: Our data suggest that IL-10 therapy for psoriasis is safe and possibly clinically effective. Consequently, its value in psoriasis and sim ilar immune diseases should be further determined. Dose-finding, placebo-co ntrolled, double-blind trials are necessary now.