Anakinra (Kineret) is the first biologic drug that has been developed specifically as an interleukin (IL)-1 receptor antagonist (Ra) and is derived from an endogenous IL-1Ra. The drug blocks the activity of IL-1 in synovial joints, reducing the inflammatory and joint destructive processes associated with rheumatoid arthritis (RA). In randomized, placebo-controlled trials of up to 52 weeks' duration, anakinra has shown efficacy both as monotherapy and in combination with other disease-modifying antirheumatic drugs (DMARDs) in adults with RA. It is subcutaneously administered and is generally well tolerated. Anakinra offers a useful addition to the range of drugs available for the treatment of RA.