Efficacy and safety of anti-TNF therapies in psoriatic arthritis: an observational study from the British Society for Rheumatology Biologics Register

Objectives. To evaluate the risk–benefit profile of anti-TNF therapies in PsA and to study the predictors of treatment response and disease remission [disease activity score (DAS)-28 < 2.6]. Methods. The study included PsA patients (n = 596) registered with the British Society for Rheumatology Biologics Register (BSRBR). Response was assessed using the European League against Rheumatism (EULAR) improvement criteria. Univariate and multivariate logistic regression models were developed to examine factors associated with EULAR response and disease remission using a range of covariates. Poisson regression was used to calculate incidence rate ratios (IRRs) for serious adverse events (SAEs) vs seronegative RA controls receiving DMARDs, adjusting for age, sex and baseline co-morbidity. Results. At baseline, the mean (s.d.) DAS-28 was 6.4 (5.6). Of the patients, 70.3% were EULAR responders at 12 months. At 6 months, older patients [adjusted odds ratio (OR) 0.97 per year; 95% CI 0.95, 0.99], females (adjusted OR 0.51; 95% CI 0.34, 0.78) and patients on corticosteroids (adjusted OR 0.45; 95% CI 0.28, 0.72) were less likely to achieve a EULAR response. Over 1776.2 person-years of follow-up (median 3.07 per person), the IRR of SAEs compared with controls was not increased (0.9; 95% CI 0.8, 1.3). Conclusions. Anti-TNF therapies have a good response rate in PsA, and have an adverse event profile similar to that seen in a control cohort of patients with seronegative arthritis receiving DMARD therapy.