OBJECTIVES: Psoriasis is a chronic inflammatory disorder. Treatment switching is common among psoriasis patients. Rates of treatment switching were compared among biologic-naive psoriasis patients initiating apremilast or biologics.

METHODS: Adults ≥18 years old with psoriasis were identified if they newly initiated apremilast or biologic treatment between January 1, 2015, and December 31, 2016, and had a minimum of 12 months pre-index and post-index continuous enrollment in the IBM MarketScan^® Commercial and Medicare Supplemental Databases. The study used 1:1 propensity score matching on baseline characteristics. Switch was defined as a claim for a new psoriasis therapy after initiation of the index medication. Days to switch was defined as the number of days between the index date and date of new therapy. Adherence while on index treatment was assessed utilizing proportion of days covered (PDC) and medication possession ratio (MPR). T-test, Wilcoxon rank-sum test, and chi-squared test were used to evaluate differences between the apremilast and biologic cohorts for continuous and categorical variables, as appropriate.

RESULTS: Each cohort had 1,645 patients. Patient characteristics were similar between groups (mean age: 48 years [both cohorts]; female: 52% [apremilast] vs 51% [biologic]; mean Charlson Comorbidity Index score: 0.45 [both cohorts]). Fewer apremilast patients switched therapies at 12 months vs biologic patients (14.0% vs 21.3%, P<0.0001). Significant differences in switch rate were observed at 6 months (6.8% vs 9.5%, P=0.0042) and 24 months (24.9% vs 35.2%, P<0.0001). Among those switched within 12 months, mean days to switch were similar (191 vs 204 days, P=0.1047). Adherence to index treatment was similar between cohorts (mean PDC: 0.81 vs 0.81, P=0.862; mean MPR: 0.83 vs 0.85, P=0.3089).

CONCLUSIONS: Biologic-naive psoriasis patients initiating apremilast demonstrated significantly lower rates of switching vs patients initiating biologics in a large US administrative claims database.