[The role of biologic agents in the therapy of ankylosing spondylitis]

Abstract

Ankylosing spondylitis is a chronic, inflammatory rheumatic disease which etiology and pathogenesis are not yet fully understood. The inflammation involves the spine and also the peripheral joints might be affected in some cases resulting in a progressive ankylosis, restricted mobility, significant disability, loss of productivity and decreased quality of life. Gene technology based new drugs of the past decade, the biologic agents, offer an alternative opportunity for the treatment of ankylosing spondylitis in comparison with the previous drugs with doubtful efficiency. In Hungary infliximab and etanercept has been registered for ankylosing spondylitis. The aim of this study was to evaluate the efficacy of infliximab and etanercept by the available randomised controlled trials. A systematic search of the literature was performed from 01. 01. 2000 to 08. 31. 2005. and the relevant publications were analysed following the concepts of evidence based medicine. 7 double blind, randomised, placebo controlled trials were identified, three for infliximab (n = 389) and four for etanercept (n = 431). Although the inclusion criteria, the duration of the trials and the primary endpoints were different, the results confirm that both drugs significantly decrease symptoms and disease activity, and this effect is sustained during the therapy, nevertheless half of the patients did not achieve the standardised criteria of 50% decrease in disease activity. Both agents are well tolerated by patients. The outcomes of long-term therapy are reassuring by open extension studies of three years. Guidelines for biologic therapy has been developed in Hungary determining the target patient group, the conditions of the therapy and also an arthritis centre network has been established. Though individual admission is feasible, biologic drugs are not under reimbursement in Hungary. High drug costs makes the implementation of this new therapeutic opportunity difficult in the daily medical practice.