Objective: To evaluate the safety and efficacy of long-term treatment of psoriasis with etanercept, 50 mg twice weekly.
Design, setting, and patients: A phase 3, randomized, double-blind trial with an open-label extension. A total of 618 adult patients with moderate to severe plaque psoriasis were studied at 39 medical centers in the United States and Canada from May 23, 2003, through June 22, 2005.
Interventions: Patients were randomized to receive placebo or etanercept for 12 weeks. Beginning with week 13, all patients (N=591) received etanercept.
Main outcome measures: Exposure-adjusted adverse event rates were calculated. Efficacy measures included efficacy and patient global assessment of psoriasis.
Results: Exposure-adjusted rates of adverse events, serious adverse events, infections, and serious infections were similar for placebo and etanercept treatments. Nonneutralizing antibodies to etanercept, observed in 18.3% of patients, had no apparent effect on safety or efficacy. Patients responded within 2 weeks to etanercept, with statistically significant differences in the Psoriasis Area and Severity Index and Dermatology Life Quality Index between the etanercept and placebo groups at week 12. At week 24, after 12 weeks of open-label etanercept treatment, patients in the original placebo group had clinical benefits comparable to those of patients in the original etanercept group. As both groups progressed through the open-label period, the Psoriasis Area and Severity Index response peaked at week 48. At week 96, 51.6% of the original placebo-treated patients and 51.1% of the original etanercept-treated patients had improvements from baseline in the Psoriasis Area and Severity Index of at least 75%.
Conclusions: Extended exposure to 50 mg of etanercept twice weekly resulted in exposure-adjusted rates of adverse events and infections similar to those in patients receiving placebo. Improvements in physician- and patient-reported measures of psoriasis severity were observed for up to 96 weeks of continuous etanercept therapy. Trial Registration clinicaltrials.gov Identifier NCT00111449.