Drug Adherence and Persistence of Patients with Moderate to Severe Psoriasis Treated with Biologic Medications in a US Commercially Insured Population

Abstract

Background: Adalimumab (ADA), certolizumab pegol (CER), etanercept (ETA), guselkumab (GUS), ixekizumab (IXE), secukinumab (SEC), and ustekinumab (UST) are biologic medications approved in the USA for the treatment of moderate to severe psoriasis. We examined drug adherence and persistence of patients with moderate to severe psoriasis who initiated these seven biologic medications. Methods: Adult patients with ≥1 pharmacy/medical claim for any of the seven psoriasis medications and ≥1 diagnosis of psoriasis in the previous 6 months between July 1, 2014 and June 30, 2019 were selected from the IBM MarketScan® Commercial Claims and Encounters Database. The index date was defined as the date of the first prescription fill. Patients were required to have continuous health plan enrollment during the 6 months prior to their index date and ≥9 months after. Patients were grouped into seven study cohorts based upon their index biologic medication. Adherence was measured using the proportion of days covered (PDC) and defined by a PDC ≥80%. Adherence and persistence with index biologic medications were examined during fixed follow-up periods of 3, 6, and 9 months, with a subpopulation analysis carried out among patients with 12 months of follow-up. Results: Among psoriasis patients with ≥9 months of continuous enrollment included in the study population, the number of those who initiated each biologic medication was 10,324 for ADA, 431 for CER, 3,092 for ETA, 821 for GUS, 1,766 for IXE, 4,132 for SEC, and 5,441 for UST. The mean age at the time of initiating biologic treatment was 46.9 years. During the 9-month follow-up period, the proportions of adherent patients (i.e., PDC ≥80%) were numerically higher among those treated with UST (59.9%) and GUS (56.9%), followed by those treated with SEC (46.1%), IXE (45.5%), ADA (44.7%), ETA (33.9%), and CER (22.0%). The proportions of patients who were persistent with their index biologic medication during the 9-month follow-up period were numerically higher among those treated with UST (70.1%) and GUS (67.8%), followed by those treated with IXE (47.3%), SEC (46.9%), ADA (28.7%), CER (14.8%), and ETA (10.7%). Conclusions: In this large healthcare claims database analysis of psoriasis patients treated with seven different biologic medications, adherence was numerically higher among those treated with UST or GUS. UST and GUS were also associated with numerically greater persistence.