The world of biologics

In March 2002 the National Institute for Health and Clinical Excellence ( NICE) published guidelines for the use of anti-TNF therapy for patients with rheumatoid arthritis ( RA). The guidelines recommended that all RA patients treated with these drugs should be enrolled on a national register which had been established by the British Society for Rheumatology ( the BSRBR). A comparison cohort of RA patients treated with traditional disease modifying drugs (DMARDs) is also being recruited. The main role of the BSRBR is to study the long-term safety of biologic drugs. Up to the end of March 2005, 9508 patients with RA had been enrolled on the BSRBR. Four thousand, three-hundred and six had been treated with etanercept, 3561 with infliximab, 1500 with adalimumab and 141 with anakinra. With regards to anti-TNF drugs, 79% remained on their original drug at six months, 65% of whom could be classified as responders. Co-prescription with methotrexate was associated with a 70% response rate. Patients with a high baseline level of disability were less likely to respond. Overall the rates of serious infection were not increased in the anti-TNF versus the comparison cohort. However the rates of skin and soft tissue infection and of intracellular infections (eg, salmonella, listeria, legionella) were increased. There were 11 cases of tuberculosis ( seven extrapulmonary). There was concern about the high mortality rates among patients with baseline pulmonary fibrosis treated with anti-TNF therapy. It is unclear whether this is related to the drug or to the underlying disease. The rates of malignancy and mortality were not increased compared to the DMARD treated group in the short term. Further follow-up is needed to determine the long term safety of these drugs.