Dr. Breban received consultancy fees, speaking fees, and/or honoraria from Schering-Plough, Wyeth, and Abbott (less than $10,000 each).
Special Articles: Biologic Agents in the Treatment of Rheumatic Diseases–The First Decade
Circulating concentration of infliximab and response to treatment in ankylosing spondylitis: Results from a randomized control study†
Version of Record online: 29 APR 2009
Copyright © 2009 by the American College of Rheumatology
Arthritis Care & Research
Volume 61, Issue 5, pages 569–576, 15 May 2009
How to Cite
Krzysiek, R., Breban, M., Ravaud, P., Prejean, M. V., Wijdenes, J., Roy, C., Henry, Y.-D., Barbey, C., Trappe, G., Dougados, M. and Emilie, D. (2009), Circulating concentration of infliximab and response to treatment in ankylosing spondylitis: Results from a randomized control study. Arthritis & Rheumatism, 61: 569–576. doi: 10.1002/art.24275
ClinicalTrials.gov identifier: NCT00439283.
- Issue online: 29 APR 2009
- Version of Record online: 29 APR 2009
- Manuscript Accepted: 28 NOV 2008
- Manuscript Received: 28 JUL 2008
A minority of patients with ankylosing spondylitis (AS) fail to respond to infliximab treatment. This study compared the circulating infliximab concentration and the presence of clinical symptoms in patients continuously treated with infliximab or after treatment interruption.
Patients with active AS were randomly assigned at week 0 to receive infliximab either at weeks 4, 6, 10, and then every 6 weeks (continuous treatment), or at weeks 4, 6, and 10 and then upon symptom recurrence (on-demand treatment). The circulating concentration of infliximab was determined early during treatment and at weeks 46 and 52 for the continuous treatment group or upon relapse for the on-demand group. Response in the continuous treatment group was defined at week 58 using the ASsessment in AS International Working Group Criteria for 20% improvement.
Among the 93 patients in the continuous treatment group, treatment failure was not associated with a low circulating concentration of infliximab, either during early treatment or at 1 year. Eleven (39.2%) of the 28 nonresponders had an infliximab concentration of >10 μg/ml at week 52, whereas 9 (13.8%) of the 65 responders had an infliximab concentration of <1 μg/ml. In the on-demand group, the infliximab concentration at relapse closely correlated with the time to relapse. However, 24 (36.9%) of 65 patients had a resurgence of clinical symptoms at an infliximab concentration of >10 μg/ml, whereas 25 patients (38.4%) had a relapse at an infliximab concentration of <0.5 μg/ml.
Responsiveness to infliximab treatment is highly heterogeneous among individuals with AS, and this parameter overcomes the circulating infliximab concentration to explain treatment success or failure.