Poor adherence to and persistence with biologics in generalized pustular psoriasis: A claim-based study using...

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 (International Classification of Diseases code L40.1) and had ≥1 inpatient or ≥2 outpatient claims.

Biologics were dispensed to 110 of 502 (22%) and 73 of 528 (14%) patients from MarketScan and Optum databases, respectively. The 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, the mean PDC was similar between age categories; good adherence was more common in patients aged 18 to 64 years (28%) versus ≥65 years (13%). Mean persistence was longer in patients aged 18 to 64 years (267 days) versus ≥65 years (242 days).

Overall, adherence and persistence were generally poor and varied according to the biologic class, database, and age. Improving adherence may help improve GPP treatment outcomes.