New Treatment for RA

June 27, 2002

Watch (General) April 16, 2002 New Treatment for Rheumatoid Arthritis

from Journal Watch Physician-authored summaries and commentary from the publishers of the New England Journal of Medicine

Anakinra (Kineret), an antagonist of the interleukin-1 receptor, recently was FDA approved for treatment of rheumatoid arthritis (RA). In this manufacturer-sponsored, double-blind, randomized trial, investigators examined the efficacy of anakinra in combination with methotrexate.

A total of 419 patients with active RA, despite at least 6 months of methotrexate therapy, received either placebo or anakinra, injected subcutaneously at doses that ranged from 0.04 mg/kg to 2.0 mg/kg. Methotrexate was continued in all patients. At 12 weeks, the proportion of patients who achieved an ACR20 response (i.e., a 20% reduction in a score that reflects several subjective and objective measures) was significantly higher among those who received 2.0-mg/kg or 1.0-mg/kg anakinra than among those who received placebo (38% and 46% vs. 19%). At 24 weeks, the percentage of responders remained significantly higher among 1.0-mg-anakinra recipients than among placebo recipients (42% vs. 23%). The most common adverse events were injection-site reactions. Five of 345 anakinra recipients withdrew because of leukopenia, which resolved in all cases.

Comment Anakinra is the latest biologic agent to be approved for use in RA, joining the 2 therapies that target tumor necrosis factor-a (infliximab [Remicade] and etanercept [Enbrel]). Upon reviewing studies of these agents in combination with methotrexate, editorialists conclude that the efficacy of anakinra "is generally similar" to that observed with infliximab and etanercept. If this assertion is true, then the choice between therapies will depend heavily on their relative costs and side-effect profiles.

Allan S. Brett, MD

Source Cohen S et al. Treatment of rheumatoid arthritis with anakinra, a recombinant human interleukin-1 receptor antagonist, in combination with methotrexate: Results of a twenty-four-week, multicenter, randomized, double-blind, placebo-controlled trial. Arthritis Rheum 2002 Mar; 46:614-24.

Dayer J-M and Bresnihan B. Targeting interleukin-1 in the treatment of rheumatoid arthritis. Arthritis Rheum 2002 Mar; 46:574-8.