Background Anti-TNF are recommended for treating axial-spondylarthritis (ax-SpA) after failure of NSAIDs and physical therapy1. Adequate patient selection is essential for their appropriate use.
Objectives To determine predictors of long-term response and drug survival on anti-TNF in ax-SpA.
Methods Patients with ax-SpA underwent treatment with anti-TNF. At baseline, 3, 6, 12 and 24 months respectively, a trained physical therapist assessed the BASMI and administered the BASDAI and BASFI questionnaires. Data collection included clinic-demographic characteristics at baseline, and ESR, CRP at baseline and at the subsequent time points. Two outcomes were taken into account in the analysis, the achievement of BASDAI 50 (a reduction of 50% or more of the score from baseline) after 12 and 24 months and the persistence on the initial medication at 24 months follow up. Statistical analysis aimed to point out differences in baseline features that can predict the mentioned outcomes.
Results Seventy-seven patients received anti-TNF treatment (33 infliximab, 28 adalimumab, 13 etanercept, 2 golimumab, 1 certolizumab pegol). Of the patients, 74% were males, 81% carried the HLA-B27 and 83% showed radiographic signs of sacro-iliitis, 83% received concomitant NSAIDs, while 26% and 22% received methotrexate and sulphasalazine respectively. Mean age ± SEM was 36.8±1.2 years, and mean disease duration was 102.0±13.0 months. Mean ESR was 22.7±2.0 mm and CRP 14.6±2.0 mg/L. The patients showed active disease (mean BASDAI 5.4±0.2) and functional impairment (mean BASFI 4.0±0.3) and reduced mobility of the cervical and lumbar spine (mean BASMI 3.5±0.2). The patients achieving BASDAI 50 response at T12, compared to the not responders, did not show any statistically significant difference with respect to age, disease duration, ESR, CRP, BASDAI, BASFI and BASMI baseline values. A trend towards an association of the BASDAI 50 achievement at T12 with a positive HLA-B27 status (p=0.06) was found. Similarly, no baseline differences in age, disease duration, ESR, CRP, BASDAI, BASFI, BASMI, nor gender or HLA-B27 status were found to be associated with the achievement or not of a BASDAI 50 response at 24 months follow-up. At 24 months, 62 patients (80%) were still under treatment, while 7 (9%) had discontinued for adverse events, and 8 (10%) had switched to an alternative anti-TNF. The patients who continued the original treatment (69% of whom were BASDAI 50 responders) showed a significantly lower BASFI value at baseline (3.7±0.3 vs 5.1±0.6, p=0.04) compared to those who had switched to an alternative drug or discontinued. The persistence on the original treatment was associated with a BASMI baseline value within the 50th percentile (BASMI ≤3.2, p=0.05).
Conclusions BASDAI 50 response was not predicted by inflammatory parameters in this cohort of patients with ax-SpA. Better physical function and of spinal mobility at baseline are associated with persistence on treatment.
Braun J, et al Ann Rheum Dis 2011; 70:896-904.
Disclosure of Interest None declared