Background Published reports suggest that patients with Spondyloartrhitis (SpA) in remission under treatment with TNFalpha inhibitors (TNFi) could obtain the same benefit at lower dose of the drug.
Objectives To evaluate effectiveness of a strategy of dose reduction of TNFi in SpA patients in clinical remission and to explore baseline characteristics predictive of maintenance of the response.
Methods Retrospective observational study, including patients with SpA meeting ASAS criteria treated with TNFi following a dose optimization protocol (lower doses or longer intervals than aproved), from 2008 to 2015. Criteria for optimization was patients with BASDAI≤2 and/or C reactive protein level (CRP)≤5 mg/L for at least 6 months. Patients who relapsed (BASDAI>2 and/or CRP>5mg/L) returned to standard dose. Clinical/analytical parameters and drug's survival time until relapse were recorded. SPSSv.17 software was used for contrast means. Survival Kaplan-Meyer curves was analysed.
Results 149 SpA patients treated with TNFi, 32/149 patients (21.5%) included in optimization protocol. 27 patients (84.37%) with increased interval between doses, remaining with reduced dosification. Table 1 shows baseline characteristics of patients on optimization group (mean±SD or proportion). 18/32 patients (56.2%,IC:39.01–73.4) maintained clinical remission with optimized dose at 36.5 months (median). Table 2 shows activity parametres of both relapsed and maintained response patients. There were either baseline differences or at optimization time between patients who maintained remission and not, but relapsed patients showed higher CRP at optimization time, without statistically significant differences. 72.2% (13/18) of patients on sutained remission were naive for TNFi, although no significant difference compared to switcher patients on the median survival (31.9 vs 20.9 months, P=0.9). No baseline predictor of sustained response at optimized dose were found. CRP<5 mg/L at optimization time showed a trend towards longer survival (43.4 vs 13.3 months), without differences statistically significant (p=0.09).
Conclusions Optimization of TNFi in SpA is possible and allows up to half of patients to maintain clinical remission, but no baseline factors predictors of sustained response after optimization was found.
Disclosure of Interest None declared