Utilization pattern of etanercept and its cost implications in moderate to severe psoriasis in a managed care population.

OBJECTIVE: To describe the utilization patterns, particularly dosage-escalation patterns, and economic implications of etanercept in the treatment of moderate to severe psoriasis in a real-world setting.
METHODS: Patients with psoriasis receiving etanercept were identified from the Integrated Health Care Information Services database and were observed for 12 months or until etanercept discontinuation (defined as gap of >60 days between prescriptions). Patients were excluded if they had other autoimmune conditions or received TNF antagonists within 6 months of the index date. Ratios of patients with dosage increase to total sample were calculated. Among patients continuing treatment for 1 year, etanercept dosage and drug costs (measured by average wholesale price) were compared for patients with and without dosage increase using the Wilcoxon signed rank test.
RESULTS: 55.2% of patients discontinued during the study year; 51.6% of patients initiated at 100 mg/week; and 34.8% who initiated at 50 mg/week required dosage increases. Among patients continuously treated for 1 year, dosage increase resulted in incremental annual drug costs of $8,440 and $9,313 for 100 and 50 mg/week, respectively (both p < 0.0001). The annual dosage of etanercept in excess of the labeled amount translated into $2,040 and $3,032 greater etanercept costs per patient in the 100 and 50 mg/week groups, respectively.
CONCLUSION: In this analysis, 33-50% of patients with psoriasis required dosage increases during their first year of etanercept therapy, resulting in increased annual treatment costs as compared with expected costs imputed from label indications. Because of patient selection criteria, the findings may not be representative of the entire population of patients with psoriasis.