Mapping the road to biologics in psoriasis and psoriatic arthritis: A nationwide drug utilization study

Background: Limited research has been conducted on whether advances in novel biologics and biosimilars have improved the treatment journey preceding biologics. Objectives: To map the overall treatment journey preceding the initiation of first biologic therapy in patients with psoriasis (PsO) and psoriatic arthritis (PsA), as well as the changes over time. Methods: Using Danish nationwide registries, we included all patients treated with a first-time biologic (2010–2018) for either PsO or PsA and reported the medical treatment journey. We used Sankey diagrams to illustrate the flow of treatment series. Results: The study included 2082 patients with PsO (62.5% male) and 1831 patients with PsA (42.3% male). Before biologics, 49.5% treated for PsO and 36.8% treated for PsA received ≥2 type therapies and 59.3% with PsO and 25.5% with PsA received ≥3 treatment series. Median time from first systemic therapy to a biologic was 3.9 years (Q1–Q3, 1.3–4.1) for PsO and 2.1 years (Q1–Q3, 0.6–5.8) for PsA. The majority of patients with PsO (1174 [56.4%]) received multiple treatment series with the same drug, while almost a third of patients with PsA (572 [31.2%]) did the same. Twelve percent of patients with PsO and 6.4% of patients with PsA repeated treatment with a drug they had already stopped for an alternative treatment. Conclusions: Although most patients are adequately managed, our findings suggest the possibility of a yet too long and complicated treatment journey before starting biologics.