Long-term safety and efficacy of etanercept in patients with rheumatoid arthritis

Patients with rheumatoid arthritis (RA) treated with etanercept (Enbrel) in controlled studies of 3 to 6 months' duration had rapid and sustained improvement of their disease, with minimal safety issues. In this study, we examine safety and clinical benefit after longer term treatment with etanercept.

All adult patients with RA with a previously inadequate response to one or more disease modifying antirheumatic drugs, and who received at least one dose of etanercept as monotherapy in controlled or open label clinical trials were evaluated for safety and clinical benefit. Adverse event rates were compared as was evidence of continued benefit over time.

Etanercept continued to be safe and well tolerated in 628 adult patients treated for a median of 25 mo (maximum 43 mo; 1109 patient-years). Nine percent of patients withdrew due to lack of efficacy and 7% due to adverse events. Most adverse events were mild, and no statistically significant increases in frequency of events were seen when patients received etanercept over longer periods of time. Clinical benefit was maintained with longterm therapy. A 100% improvement in individual disease activity measures was achieved by 17% to 28% of the patients. Fifty-five percent of patients who were taking corticosteroids (mean dose at baseline 6.6 mg/day) decreased or discontinued corticosteroid therapy while maintaining control of their arthritis symptoms.

Etanercept continued to be safe and well tolerated, and its clinical benefit was sustained for a median of 25 mo and for as long as 43 mo in patients with RA.