The use of TNF blocking agents in psoriatic arthritis (PsA) is increasing, and the South Swedish Arthritis Treatment Group register has followed patients with PsA for more than 5 years.
Researchers at Lund University Hospital aimed to present efficacy and tolerability data of TNF-blocking agents on PsA in clinical practice, and also to study potential predictors for drug survival. The researchers included patients (n=261) with active PsA starting anti-TNF therapy for the first time in southern Sweden. Basal characteristics, disease activity measures, and termination reason for TNF-blockers were prospectively collected during the period from April 1999 to September 2006. Cox proportional hazard models were used to investigate predictors for treatment termination.The study found that, overall, response rates at 3-12 months for VASglobal50 and VASpain50 were about 50%, whereas response rates for EULAR overall and EULAR good were around 75% and 55%, respectively. Concomitant MTX (HR=0.64 (95% CI 0.39-0.95), p=0.03), etanercept (HR=0.49 (0.28-0.86), p=0.01), and high CRP-levels (HR=0.77 (0.61-0.97), p=0.03) at treatment initiation were associated with better overall drug survival. The improved drug survival of concomitant MTX appeared to be related to significantly fewer drop outs because of adverse events (HR= 0.24 (0.11-0.52), p<0.01). The TNF-blockers were well tolerated with a rate of serious adverse events of 5-6% per year. No unexpected serious adverse events were observed. The researchers concluded that concomitant MTX and high CRP-levels are associated with treatment continuation of anti-TNF therapy in patients with PsA regardless of joint distribution. The positive effect of MTX was primarily linked to fewer drop outs because of adverse events.(Source: Kristensen LE, Gulfe A, Saxne T, Geborek P. Efficacy and tolerability of anti-TNF therapy in psoriatic arthritis patients: Results from the South Swedish Arthritis Treatment Group Register. Ann Rheum Dis. 2007 Jul 20; [Epub ahead of print] : August 2007)