[Four-year observation of etanercept therapy for rheumatoid arthritis in a single German center]

Abstract

The tumor necrosis factor blocking agent etanercept is effective in the treatment of chronic inflammatory diseases. Previously published studies provided no evidence for an elevated frequency of severe adverse events under therapy. The present work documents efficacy and safety of long-term treatment with etanercept up to four years in 29 patients with rheumatoid arthritis in single German study center. Follow-up examinations were conducted at monthly intervals. The response was assessed in an intention-to-treat analysis (last observation carried forward) according to the ACR and EULAR criteria. The evaluation is based on 95 patient years, the median observation period was 50 (4-52) months. After four years, 21 patients were still in the study. Reasons for study dropouts were inefficacy (n=3), severe adverse events (n=1), long distance to study center (n=2), scheduled surgery (n=1), and desire for pregnancy (n=1). Morning stiffness, the number of painful and swollen joints, C-reactive protein, erythrocyte sedimentation rate, and DAS28 significantly decreased within 6 months. At their most recent visit, 26 patients (90%) had achieved the ACR20, 17 patients (59%) the ACR50, and 6 patients (21%) the ACR70 criteria. Subject to the EULAR criteria, 14 patients (48%) responded well and another 12 patients (41%) moderately well. Severe adverse events occurred in the form of a sigma perforation with subsequent sepsis (week 17), suture insufficiency (twice) following rupture of an Achilles tendon (weeks 3 and 9), pneumonia (week 121), and breast cancer (week 197). In our patients, long-term treatment with etanercept continued to be effective and safe up to four years. Severe adverse events were rare and not more frequent than expected. For the detection of uncommon or late occurring severe adverse events under the treatment with biologic agents, documentation in central registers should be encouraged.