Infliximab in the treatment of rheumatoid arthritis

Infliximab was the first monoclonal antibody to human necrosis factor alpha (TNFalpha) developed for treating rheumatoid arthritis (RA). This chimeric antibody binds with high affinity to both soluble and trans-membrane TNF and is able to reduce synovial inflammation, bone resorption and cartilage degradation. The efficacy of infliximab has been observed in active RA despite treatment with multiple disease modifying anti-rheumatic drugs (DMARDs), and in early disease with no prior treatment by methotrexate (MTX). Infliximab has been shown to reduce joint inflammation and to slow radiographic progression, in both clinical and non-clinical responders. Recent data suggest that using infliximab early in RA treatment increases the percentage of clinical remission and allows infliximab discontinuation. The recommended dosage of 3 mg/kg could be increased up to 10 mg/kg with partial efficacy of the dose escalation. Antibodies to infliximab have been observed in 7% to 61% of patients and are associated with a low trough level of infliximab and secondary response failure. Their occurrence could be prevented by co-medication with MTX. The combination of DMARDs other than MTX with infliximab was found to be safe and efficacious. Infections, principally tuberculosis, are increased in treated patients, and the risk is greater at higher dose. Even if the treatment is generally safe and well tolerated, patients treated with infliximab should be closely monitored.