Etanercept: new preparation. Useful after methotrexate failure in inflammatory rheumatism

There is no reference second-line treatment for patients with rheumatoid arthritis, juvenile chronic arthritis, psoriatic arthropathy or ankylosing spondylitis after failure or intolerance of a slow-acting antirheumatic drug such as methotrexate. Etanercept, a immunosuppressant targeting TNF-alpha (like infliximab), is now approved in France for use in these situations, with the exception of spondylitis. In the second-line treatment of adults with rheumatoid arthritis, the clinical evaluation dossier on etanercept contains data from dose-finding studies and two placebo-controlled trials involving patients in whom several single-agent treatments had failed. At a dose of 25 mg subcutaneously twice a week, etanercept worked partially in about half the patients. Without direct comparisons, the place of etanercept relative to other slow-acting antirheumatic drugs is difficult to establish. From indirect comparisons, etanercept seems a slightly better treatment option than infliximab. In the first-line treatment of rheumatoid arthritis, one trial showed that etanercept worked faster than methotrexate, but there was no significant difference between the two treatments after two years. Little is known about the efficacy of etanercept in patients with juvenile chronic arthritis who do not respond adequately to methotrexate. There are no comparative trials. One double-blind placebo-controlled trial showed that etanercept, when it worked, remained active for at least 7 months. In one trial, etanercept was more effective than placebo in patients with psoriatic arthropathy and ankylosing spondylitis who continued to receive their usual treatment, which included a slow-acting antirheumatic drug in about 50% of cases. More than 50% of patients treated with etanercept have a cutaneous reaction to the injection. These reactions are usually mild or moderate. Active pharmacovigilance is needed, given its mechanism of action, and previous notifications of a wide variety of adverse effects (even though it is sometimes difficult to establish a foolproof link between etanercept and the adverse effect). Long-term studies of large numbers of patients are needed to determine the precise risk of side effects including haematological, infectious, neurological, oncological and immunological effects. In practice, methotrexate remains the first-line treatment for inflammatory arthritis. Etanercept can be a useful second-line treatment, especially in juvenile chronic arthritis.