Rational use of new and existing disease-modifying agents in rheumatoid arthritis

Abstract

Because of radiographic evidence of progressive bone loss and the inability to eliminate synovial proliferation with methotrexate, it became apparent that therapy for rheumatoid arthritis needed further advancement. Methotrexate is not a remission-inducing drug and may have dose-limiting toxicity. In the past 2 years, three new disease-modifying antirheumatic drugs (DMARDs) have been approved: leflunomide, etanercept, and infliximab. Each of these agents has demonstrated efficacy compared with placebo in randomized, controlled studies. Because methotrexate had a dominant therapeutic role, the new drugs were also studied in combination with it. Other established DMARDs, such as sulfasalazine and hydroxychloroquine, have also demonstrated efficacy when used together with methotrexate. The results of these combination studies clearly demonstrate that clinical responses can be meaningfully improved when new and existing DMARDs are added to methotrexate. Although toxicity remains a serious concern when powerful immune modulators and antimetabolites are used in combination, relatively few serious adverse events have been reported during 2-year treatment periods. It has also become apparent that combinations of new DMARDs and methotrexate virtually halt radiographic progression over 2 years. The new agents are expensive, but annual costs must be weighed against the personal and societal expense of joint arthroplasty, hospitalizations, disability, and diminished quality of life that accompanies poorly controlled rheumatoid arthritis. The ultimate value of combination DMARD therapy with methotrexate will be determined by long-term data on safety, efficacy, and effects on radiographic deterioration of bone. Additional long-term observational data on the incidence of joint arthroplasty and disability will help to place the issue of societal costs in a better perspective. This will allow the value of aggressive treatment to be established with certainty.