Infliximab treatment in ankylosing spondylitis: an observational study.

Objective: To investigate efficacy, toxicity, and drug discontinuation in patients with ankylosing spondylitis (AS) treated with infliximab.

Methods: 35 patients with AS with mean (SD) age 42.5 (12.6) years and mean (SD) disease duration 14.5 (8.0) years were studied for 2 years. Patients entering the study had a negative tuberculin skin test, were fully informed about the treatment, and were followed up regularly. Infliximab, 5 mg/kg weight, was given intravenously at weeks 0, 2, 6, and every 8 weeks thereafter. Data concerning infliximab tolerability, adverse events, interval, and drug discontinuation were all recorded. Clinical improvement according to the BASDAI and the Ankylosing Spondylitis Assessment Study group (ASAS) 20%, 40%, and ASAS 5/6 response criteria were recorded.

Results: After 1 year, 20 (57%) patients achieved the BASDAI 50% response criteria, 25 (71%) achieved ASAS 20%, 23 (66%) reached ASAS 40%, and 18 (51%) attained ASAS 5/6. After 2 years' treatment, 11 (31%) patients achieved BASDAI 50% response criteria, 14 (40%) ASAS 20%, 11 (31%) ASAS 40%, and 9 (26%) ASAS 5/6. Clinical improvement was associated with an improved BASFI and reduction of CRP. After 2 years' treatment, "infliximab survival" was 89%. Treatment was well tolerated and adverse events were mild; 3 patients discontinued the study.

Conclusion: Infliximab was effective, safe, and well tolerated in patients with AS.