Adalimumab and etanercept adherence, persistence and switch in the treatment of psoriatic arthritis: 10-year real-life analysis

Objectives: The objective of this study was to calculate adherence, persistence and 10-year switches in patients with PsA, by comparing adalimumab and etanercept in real life. Methods: The authors conducted a retrospective, observational, pharmacological and non-interventional study taking into consideration the dispensations of the study drugs at the Hospital Pharmacy, from 1 January 2007 to 31 December 2018. In the study, the authors considered adalimumab and etanercept. The authors calculated adherence to treatment through the relationship between received daily dose (RDD) and prescribed daily dose (PDD), and calculated persistence to treatment as the difference in days between the first and last dispensation. Results: The authors enrolled 113 patients, 60 treated with adalimumab and 53 with etanercept. Adherence levels were 0.83 for adalimumab and 0.84 for etanercept. Switches occurred in 42% of adalimumab and in 47% of etanercept prescriptions. Conclusion: In the treatment of PsA, persistence and switches are a problem for patients who cannot follow a consistent therapy over time, for clinicians who have to manage therapy suspension and changes, and for the National Health System that must procure and pay for a high number of drugs without information on their real value in terms of efficacy and safety of use.