Pbi90 the Economic Impact of the Introduction of Infliximab-Biosimilar: An Empirical Analysis Using the Tuscany Healthcare Administrative Databases

Abstract

Objectives: The main objective was to determine the monthly average dose for biologic drugs used for psoriasis (PSO), psoriatic arthritis (PsA) and ankylosing spondylitis (AS). Methods: A retrospective analysis of administrative databases of two regions and 1 local health unit was performed. All adult patients with a diagnosis of PSO, PsA or AS (identified byICD-9-CM/exemption code)between 01/01/2011 and 30/06/2017 (inclusion period) were screened. Only patients with biologic drugs were included. Date of first prescription of biologic drugs during inclusion period was defined index date(ID). Patients were followed-up for 6 months after ID. Monthly average dose(mg) and persistence to treatment were estimated after 6 months of follow-up. Results: Percentage(%) of patients in the 3 diseases treated with biologic drugs in each indication was: 1.1 in PSO, 37.4 in PsA and 17.8 in AS. 6179 patients were included: 2373 (mean age 50.2, 60.4% male) PSO-patients, 2756 (mean age 53.0, 50.6% male) PsA-patients, 1050 (mean age 47.0, 59.0% male) AS-patients. Results focused on subcutaneous biologic drugs frequently prescribed for the 3 diseases of interest. Etanercept monthly average dose was 152 for PSO, 155 for PsA and 147 for AS patients. For adalimumab, PSO-patients had a monthly average dose of 69, PsA-patients 73 and AS-patients 70. Monthly average dose for secukinumabtreated patients was 255 for PSO, 183 for PsA and 154 for AS. The percentage of patients persisting with treatment (6 months of follow up) was: for etanercept 77 for PSO, PsA and AS patients; for adalimumab, 76 for PSO, 78 for PsA and 74 for AS patients; for secukinumab 91 for PSO, 85 for PsA and 60 for AS. Conclusions: This cohort study described real-world dosing patterns of biologic drugs used by patients affected by PSO, PsA or AS, giving an insight into the everyday clinical practice.