Use of systemic and biological therapy in patients with moderate-to-severe psoriasis

BACKGROUND: Patients with moderate-to-severe psoriasis are candidates for systemic treatment, but it is unknown how many receive such therapy at a national level in Denmark.

OBJECTIVES: We aimed to determine the prevalence of conventional systemic therapy use in patients with moderate-to-severe psoriasis and, further, to investigate the time to discontinuation of conventional systemic therapy and initiation of biological therapy among biologic-naïve patients.

METHODS: This registry-based study identified a cohort of patients with psoriasis in Denmark. We estimated the prevalence of moderate-to-severe psoriasis at a national level using registry data. Inverse probability weighting was used to mitigate potential selection bias in the prevalence estimate of moderate-to-severe psoriasis. Analyses were then performed on the weighted cohort.

RESULTS: Of patients with psoriasis in Denmark, 10.9% were estimated to have moderate-to-severe psoriasis, of whom 62.3% received either conventional systemic or biological therapy, meaning 37.7% who were considered candidates for systemic therapy did not receive any systemic treatment. The study demonstrated that, comparing previous time periods with more recent years: (i) time on conventional systemic therapy for patients with moderate-to-severe psoriasis has become shorter, with a median (interquartile range) of 3.0 years (0.6-10.0) in 1985-1994 vs. 0.6 years (0.3-2.0) in 2014-2018; (ii) more patients initiated biologics as second-line therapy, with 69.5% in 2010-2013 vs. 71.2% in 2014-2018; and (iii) the median time from initiation of systemic therapy to initiation of biological therapy decreased from 13.3 years (11.5-16.8) in 2010-2013 to 1.9 years (1.7-2.4) in 2014-2018.

CONCLUSIONS: This study found that nearly 37.7% of Danish patients with moderate-to-severe psoriasis do not receive systemic treatment even though they would qualify for this. Furthermore, for patients treated with conventional systemics, drug survival decreased during the observation period.