OBSERVE-5 interim analysis: an observational postmarketing safety registry of etanercept for the treatment of psoriasis.

Background: Etanercept is approved for the treatment of chronic moderate to severe plaque psoriasis in adults.

Objective: We sought to evaluate the long-term safety of etanercept in a real-world clinical setting. Assessment of etanercept efficacy was a secondary objective.

Methods: OBSERVE-5 is a 5-year observational safety registry initiated in May 2006 at multiple sites in the United States and Canada. Data collection includes the number of serious adverse events, serious infectious events, and prespecified events of medical interest. Efficacy data include body surface area assessments, physician and patient global assessments of psoriasis, and the Dermatology Life Quality Index. This interim analysis presents data from the first 3 years of the follow-up period.

Results: A total of 2511 patients were enrolled. Of 1890 patients continuing in the registry after 3 years, 113 were inactive for 1 to 2 years, and 115 were inactive for longer than 2 years. The 3-year incidence proportions of serious adverse events and serious infectious events based on Kaplan-Meier methodology were 0.14 and 0.04, respectively. The observed numbers of patients experiencing lymphoma, serious infectious events requiring hospitalization, nonmelanoma skin cancer, and malignancies excluding nonmelanoma skin cancer were not higher than the expected number of cases estimated from a large US administrative health claims database.

Limitations: The registry lacks a control group, and the study is too small to measure the frequency of rare events.

Conclusion: Etanercept demonstrated good tolerability in patients with plaque psoriasis in the clinical setting in this interim analysis. No new or unexpected safety concerns were observed.