Efficacy and safety observed during 24 weeks of efalizumab therapy in patients with moderate to severe plaque psoriasis.

Objective: To assess the efficacy and safety of a 24-week course of efalizumab.

Design: Phase 3, randomized, double-blind, parallel-group, placebo-controlled 12-week study followed by a 12-week open-label study.

Setting: Outpatient dermatology clinics. Patients A total of 556 patients with moderate to severe chronic plaque psoriasis who were seeing an outpatient dermatologist were included in the study. Intervention For weeks 1 to 12, the 556 patients were randomized to receive 1 mg/kg of efalizumab weekly or placebo subcutaneously. For weeks 13 to 24, 516 of these patients received 1 mg/kg of efalizumab weekly.

Main Outcome Measures: Proportion of patients with a 75% or greater improvement in Psoriasis Area and Severity Index (PASI-75), a 50% or greater improvement in PASI (PASI-50), static Physician's Global Assessment (sPGA) rating of minimal or clear, and improvements in Dermatology Life Quality Index (DLQI), itching scale, and Psoriasis Symptom Assessment (PSA) frequency and severity scores at weeks 12 and 24. Safety was evaluated by reviewing adverse events, laboratory parameters, vital signs, and anti-efalizumab antibodies.

Results: At week 12, 26.6% of efalizumab-treated patients achieved PASI-75 and 58.5% achieved PASI-50. After 24 weeks of continuous efalizumab therapy, PASI responses increased: 43.8% of patients achieved PASI-75 and 66.6% achieved PASI-50. The percentage of patients who achieved an sPGA rating of minimal or clear increased from 25.7% to 35.9%. The mean percentage of improvement in all patient-reported outcomes (DLQI, itching scale, and PSA frequency and severity scores) at week 12 was maintained at week 24 (DLQI, 49.2%; itching scale, 42.2%; PSA frequency, 47.6%; PSA severity, 47.3%). There was a decline in overall reported adverse events from weeks 1 to 12 (80.4%) to weeks 13 to 24 (63.2%) without evidence of cumulative toxic effects. Conclusion Extending efalizumab treatment from 12 to 24 weeks leads to improved efficacy and maintenance of quality of life with no evidence of cumulative toxic effects noted in patients with moderate to severe chronic plaque psoriasis.