Comparison of Drug Survival Rates for Adalimumab, Etanercept and Infliximab in Patients with Psoriasis Vulgaris

Background: Adherence to treatment is an indicator of treatment success. Long-term data on adherence to biologic treatment in psoriasis are lacking.

Objectives: To compare the tumour necrosis factor (TNF)-α inhibitors regarding drug survival rate and safety in patients with psoriasis.

Methods: This study is based on data from the Danish nationwide database DERMBIO covering patients with psoriasis treated with a biologic agent. All patients who received anti-TNF-α treatment in academic referral centres were included. Baseline data, adverse events, time on treatment and reason for stopping treatment were recorded. Hazard ratios (HRs) for factors determining drug survival were calculated by logistic regression.

Results: In total, 882 treatment series with etanercept (n = 311), adalimumab (n = 427) or infliximab (n = 144) were administered to 747 patients. Significant predictors of drug survival were: sex, the anti-TNF-α agent and the previous response to an anti-TNF-α agent. In the group of anti-TNF-α-naïve patients the longest drug survival was observed for infliximab, followed by adalimumab [HR vs. infliximab 3·70, 95% confidence interval (CI) 1·99-6·89] and etanercept (HR vs. infliximab 3·18, 95% CI 1·72-5·86). The 4-year drug survival is in the range of 40% for etanercept or adalimumab vs. 70% for infliximab. There was no difference in number of adverse events.

Conclusions: The overall efficacy of anti-TNF-α drugs diminishes with time, as envisaged by the progressive loss of patient adherence to treatment. The major reasons for stopping treatment were loss of efficacy, followed by adverse events. Infliximab had the best patient retention ability, with 70% of patients still being on the drug after 4 years of treatment.