Background Biologic drug survival is defined as the time from initiation of biologic therapy to discontinuation, which can be due to ineffectiveness, adverse events or other reasons. It is an important measurement of overall treatment success in psoriasis and a priority in clinical practice. Clinical trials do not provide information about the long-term drug survival of biologic agents and possible covariates that may affect the drug survival

Purpose We sought to determine the drug survival of adalimumab (ADA), etanercept (ETN) and ustekinumab (UST) in patients with moderate to severe psoriasis, and to elucidate covariates that influence drug survival.

Material and methods A retrospective observational study was conducted. Data were obtained from clinical records of 122 patients treated with biologic agents for psoriasis between 2007 and 2016 at University Hospital Germans Trias i Pujol (Badalona, Spain). Drug survival was analysed using Kaplan-Meier plots, and Cox regression analysis was used to estimate the influence of covariates

Results We analysed 172 treatment sequences, from which 83 treatments were discontinued. Ineffectiveness was the most common reason for drug discontinuation. The mean drug survival was 32.7 months. The estimated 1-, 2- and 3 year drug survival rates were highest for ustekinumab, followed by adalimumab and etanercept (78.3%, 64.8% and 59.1% for UST; 72.4%, 63.4% and 56.5% for ADA; 67.4%, 52.9% and 49.2% for ETN). The confounder-corrected hazard ratio of drug discontinuation was not significantly lower for ustekinumab compared to adalimumab, and significantly higher for etanercept compared to adalimumab. Multivariate analysis showed that BMI>35 kg/m² and previous failure of biologic treatment were significant negative predictors of drug survival. Female sex was strongly associated with drug discontinuation due to adverse events.

Conclusion Ustekinumab was the drug with the best probability of survival. However, there were not significant differences compared with adalimumab. Etanercept had a significantly worse probability of drug survival compared to both ustekinumab and adalimumab. Covariates that may affect negatively the drug survival are BMI>35 kg/m² and previous failure of biologic treatment.

References and/or Acknowledgements I would like to thank Dr Josep Roca for his help with the statistical analysis.

No conflict of interest