Drug Discontinuation Due to Inefficacy in Ankylosing Spondylitis Patients Treated with Anti-TNF Drugs

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Presentation Number:CRC11

Presentation Time:11/6/2007 12:00:00 PM

Title:Drug Discontinuation Due to Inefficacy in Ankylosing Spondylitis

Patients Treated with Anti-TNF Drugs: Results from the British Society for

Rheumatology Biologics Register (BSRBR)

Category:Drug Effectiveness in Rheumatology (not to include randomized

controlled trials)

Author(s): Lord, Mark Lunt, Kath , Deborah P M Symmons, Kimme L.

Hyrich, on behalf of the BSR Biologics Register. University of Manchester,

Manchester, United Kingdom

Background: Cytokines play a major role in the pathogenesis of Ankylosing

Spondylitis (AS). Elevated levels of tumour necrosis factor alpha (TNF) have

been found in the sacroiliac joints and areas of new bone formation in AS

patients. Clinical trials have shown anti-TNF agents to be very effective in

controlling symptoms in patients with AS, although the benefits have not

been universal. The purpose of this analysis was to describe anti-TNF drug

survival in a national cohort of patients with AS and to identify factors

associated with stopping for inefficacy.

Methods: The BSRBR systematically collects information on patients in the UK

receiving anti-TNF for rheumatic disorders. The current analysis is limited

to patients with AS who had completed at least 6-months of follow-up by

31/01/2007. Drug survival was estimated using Kaplan-Meier curves.

Multivariate Proportional hazards models were used to identify

independent predictors of stopping for inefficacy and included the following

baseline characteristics: age (in decades), gender, disease duration, NSAID

and methotrexate (MTX) use, and raised inflammatory markers (defined as ESR

> 28mm/hr and/or CRP>20 mg/L).

Results: 568 patients were included in the analysis. Median age at start of

therapy was 43 years and 81% were male. 64% of patients had raised

inflammatory markers at the start of therapy and 15% reported peripheral

joint disease. The median disease duration was 13 years (IQR 6, 21).

At baseline, 287 (51%) started etanercept, 246 (43%) infliximab and 35 (6%)

adalimumab. 413 (72 %) were receiving NSAIDS and 207 (36%) were receiving

concurrent MTX. After a median follow-up per patient of 2.0 years, 13% of

subjects had stopped for inefficacy and 10% had stopped for adverse events.

Overall drug survival was 80%, 69% and 61% at 1, 2 and 3 years respectively.

Patients with raised inflammatory markers at the start of therapy were less

likely to stop for inefficacy. Older patients were more likely to stop for

inefficacy. Concurrent MTX use did not significantly influence drug

survival.

Conclusion: Overall, drug survival in AS patients was good, with 69 per cent

of patients still taking their first anti-TNF drug at 2 years and only 13%

stopping for inefficacy. Patients with raised inflammatory markers at the

start of therapy were less likely to discontinue for inefficacy, identifying

a group of patients who may be more responsive to anti-TNF therapies.

Disclosures: P. Lord, None; M. Lunt, None; K. , None; D.P. Symmons,

None; K.L. Hyrich, None.