Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Long-Term Drug Survival of Anti-TNF Therapy in Ankylosing Spondylitis.

Li1,  Qiang, Seah2,  Michelle Y., Burgess3,  John A., Dharmage3,  Shyamali, Martin1,  Belinda J., Buchanan1,  Russell, Schachna1,  Lionel

Austin Health, Melbourne, Australia
Austin Health, Melbourne, Australia
University of Melbourne, Melbourne, Australia

Background:

Unlike rheumatoid arthritis, the long-term efficacy and safety of TNF inhibitor (TNFi) therapy in ankylosing spondylitis (AS) is largely unknown. We examined drug survival (ie, continuation) rates of TNFis among a large cohort of AS patients.

Methods:

All biologically-naive patients with active AS commencing TNFi therapy in a single center were followed to March 31, 2010. The effectiveness of treatment was examined by drug survival using life table analysis and multivariate Cox proportional hazards analysis.

Results:

We examined 209 consecutive patients who received a total of 326 TNFi courses for active AS over 581.0 patient-years; the median treatment duration was 32.9 months (range: 0.4–68.3). The first TNFi was infliximab in 87 (41.6%), adalimumab in 66 (31.6%) and etanercept in 56 (26.8%). Men constituted 153 (73.2%) of the study sample and the mean age at inclusion was 42.4 (SD 11.9) years with disease duration of 19.1 (SD 11.3) years. At the end of follow-up, 128 (61.2%) remained on their first TNFi while 52 (24.9%) had switched to their second, and 24 (11.5%) to a third TNFi. The reasons for TNFi discontinuation were secondary inefficacy (34.6%), adverse event (24.1%), primary inefficacy (21.1%), convenience (12.0%) and other (8.3%). Treatment discontinuation due to adverse events occurred more commonly for infliximab 19 (17.0%) compared with adalimumab 6 (5.0%) (odds ratio (OR) 3.9, 95CI, 1.4–12.4) and etanercept 7 (7.5%) (OR 2.5, 95CI, 0.9–7.4). Only 13 patients (6.2%) had ceased TNFi therapy entirely (primary inefficacy (3), adverse event (5), planning to conceive (1), other (4)). Drug survival for the first TNFi therapy was 0.82, 0.72, 0.60, 0.53 and 0.43 at 6, 12, 24, 36 and 60 months, respectively. At similar time points, drug survival for the second TNFi was lower only for the first 12 months: 0.74, 0.64. 0.58, 0.52 and 0.44, respectively (p=0.32). For the second course of TNFi, primary inefficacy to the first TNFi was associated with drug survival at 6 months of only 0.50 compared with 0.84 for prior secondary inefficacy and 0.82 for adverse events (p=0.11). Survivor function was equivalent for all TNFis, by log rank test. Predictors for treatment discontinuation in multivariate analysis were absence of HLA-B27 (hazards ratio (HR) 2.0, 95CI, 1.1–3.8) and female sex (HR 2.0, 95CI, 1.3–3.0).

Conclusions:

Switching to an alternative TNFi is common in AS but few patients entirely cease treatment. Primary inefficacy to initial TNFi is associated with low continuation rates of a second TNFi.

To cite this abstract, please use the following information:
Li, Qiang, Seah, Michelle Y., Burgess, John A., Dharmage, Shyamali, Martin, Belinda J., Buchanan, Russell, et al; Long-Term Drug Survival of Anti-TNF Therapy in Ankylosing Spondylitis. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1942
DOI: 10.1002/art.29707

Abstract Supplement

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