In the open extension of the first randomized controlled trial of infliximab therapy for patients with ankylosing spondylitis (AS), 2-year follow-up data showed that patients treated with infliximab had less radiographic progression than patients treated with conventional therapies. Baraliakos and colleagues have now published results from follow-up consultations 4 years after the initiation of infliximab treatment.

The 33 trial participants were treated intravenously with infliximab every 6 weeks for 3 years. Patients were then reinfused with infliximab if, and when, clinical relapse occurred; the median time to relapse was 14.6 weeks. Patients who started the study with radiographic damage showed statistically significant worsening of the chronic spinal changes after 4 years (P = 0.003): 13 of 26 patients showed some radiographic changes, with 10 of these patients classified as having definite radiographic deterioration. Patients who started the study with no radiographic damage did not show significant deterioration (P = 0.08): although four of seven patients showed some changes at the final follow-up, only one of these patients was classified as having definite deterioration. Overall, radiographic change was less pronounced for patients treated with infliximab than for patients who participated in a previous cohort study of conventional AS therapy; however, owing to differences in the average disease activities of the two patient groups, larger trials and a different methodology might be required to confirm this finding.

The authors conclude that although infliximab might decelerate radiographic progression in patients with AS, this anti-TNF therapy does not result in complete inhibition of this process.