Poor adherence and persistence to biologics in generalized pustular psoriasis: A claim-based study using real-world data from two large US databases

Generalized pustular psoriasis (GPP) is a rare skin disease characterized by episodes of widespread sterile pustules. A retrospective cohort study using data from the US IBM® MarketScan® Commercial and Optum® Clinformatics® Data Mart databases between October 1, 2015 and March 31, 2020 was performed to describe adherence and persistence to biologics in patients with GPP. Patients were aged ≥18 years with newly diagnosed GPP (ICD code L40.1) and had ≥1 inpatient or ≥2 outpatient claims. Biologics were dispensed to 110/502 (22%) MarketScan and 73/528 (14%) Optum patients. Mean proportion of days covered (PDC) (range) was similar in both databases (MarketScan, 65% [8–100%]; Optum, 59% [8–99%]), and good adherence (≥80% PDC) was uncommon (MarketScan, 36%; Optum, 24%). Mean (standard deviation) persistence was similar in both databases (MarketScan, 287 [122] days; Optum, 261 [134] days). In Optum, mean PDC was similar between age categories; good adherence was more common in patients aged 18–64 (28%) versus ≥65 years (13%). Mean persistence was longer in patients aged 18–64 (267 days) versus ≥65 years (242 days). Overall, adherence and persistence were generally poor and varied according to biologic class, database, and age. Improving adherence may help improve GPP treatment outcomes.