Infliximab

Abstract

Infliximab is a chimaeric monoclonal antibody which binds to and inhibits the activity of tumour necrosis factor-alpha (TNFalpha), a cytokine which is involved in the development of both Crohn's disease and rheumatoid arthritis. In patients with treatment-resistant Crohn's disease, infliximab was significantly more effective than placebo in the relief of symptoms. 50 to 89% of patients responded to infliximab and most of them also achieved remission. Patients showed signs of relapse 8 to 12 weeks after a single infusion but responded to additional infusions of the drug. Infliximab was also effective in closing the fistulae in 68% of patients with fistulising Crohn's disease; the response rate with placebo was 26%. Infliximab achieved a clinical response in 44 to 81% of patients with refractory rheumatoid arthritis. Following a single infusion, symptom recurrence was evident after 6 to 12 weeks, but subsequent infusions re-established a clinical response. Concurrent methotrexate appeared to prolong the effects of infliximab in this patient group. Anti-infliximab and anti-double-stranded DNA antibodies developed in some patients, particularly those who received multiple infusions of infliximab. Acute adverse events consistent with hypersensitivity occurred in some patients who received multiple infusions of infliximab. Infection occurred slightly more frequently with infliximab than with placebo. Infliximab appears to be an effective therapy for patients with treatment-resistant or fistulising Crohn's disease or refractory rheumatoid arthritis. The tolerability, long term efficacy and optimal dosage regimen need to be further defined in comparative trials before the full potential of infliximab is realised in these patients.