Anakinra

Anakinra, a recombinant human interleukin-1 (IL-1) receptor antagonist, is the first biological agent approved to block the pro-inflammatory effects of IL-1 in patients with rheumatoid arthritis. In a double-blind, randomised trial in 472 patients with active, severe or very severe rheumatoid arthritis, recipients of subcutaneous anakinra 150 mg/day achieved higher response rates [assessed using the American College of Rheumatology (ACR) composite score] and accumulated more mean productivity days after 6 months than placebo recipients. However, the response rates and accumulated productivity days of patients receiving subcutaneous anakinra 30 or 75 mg/day for 6 months were similar to those of placebo. With respect to the total Genant radiographic scores, the same study showed that all anakinra treatment regimens slowed disease progression after 6 months to a greater extent than placebo. In double-blind, randomised trials in patients with rheumatoid arthritis, combined treatment with anakinra and methotrexate was associated with higher ACR 20, 50 and 70 response rates than with methotrexate alone. Anakinra, used alone or in combination with methotrexate, was generally well tolerated, with the most frequent adverse event being a mild injection-site reaction of transient duration. Infections requiring antibacterial therapy or hospitalisation occurred more commonly in anakinra recipients than in placebo recipients, but were a rare cause for discontinuation of anakinra therapy (approximately 1%) in clinical trials.