Real-world Prescription Pattern, Discontinuation and Costs of Ibrutinib-Naïve Patients with Chronic Lymphocytic Leukemia: An Italian Healthcare Administrative Database Analysis.

BACKGROUND AND

objectiveIn order to integrate the existing and inconsistent information from clinical trials and real-world practice on chronic lymphocytic leukemia (CLL) treated with ibrutinib, this analysis aimed to describe the prescription pattern of new users of ibrutinib affected by CLL, focusing on discontinuation, severe adverse events (AEs) and change of treatment, and to assess the integrated healthcare expenditure from the Italian National Health System (INHS) perspective.

methodsStarting from the ReS database, adults with at least a supply of ibrutinib (ATC code L01XE27) were selected from 01/01/2016 to 12/31/2017. Those without any ibrutinib supply in the year before the index prescription were considered new users. Out of them, only patients with at least a primary or secondary in-hospital diagnosis of CLL (ICD-9-CM code 204.1*) from 01/01/2013 to 12/31/2018 were further broken down according to the ibrutinib's line treatment (first line-FL; second or later line-SLL) and analysed. They were characterized by sex and age in the selection period. Mean annual consumption (defined daily doses [DDD]), treatment discontinuation, changes of therapy, interruptions and healthcare costs in charge of the INHS were assessed during two follow-up years.

resultsOut of more than 5 million inhabitants of the ReS database, 69 new ibrutinib users and diagnosed with CLL in 2016 (incidence: 1.6 × 100,000) and 41 in 2017 (incidence: 0.9 × 100,000) were selected. Of these, 21 (19.1%) were FL ibrutinib users and 89 (80.9%) were SLL ones, mostly males and with mean ages (±SD) of 65 ± 14 and 70 ± 10, respectively. The mean annual consumption among FL users decreased from 222.2 DDD per patient treated to 216.0 DDD, while increased among SLL patients from 238.6 DDD to 260.1 DDD, in the first and second follow-up year, respectively. The discontinuation rate was about 40% in the first year, similarly among FL and SLL users. SLL patients discontinued more frequently (52.8% vs 20.0%) in the second year. Very few AEs were recorded. The 62.5% of FL and 55.6% of SLL users discontinuing ibrutinib in 1-year follow-up, while one SLL patient (5.3%) in the second year changed therapy. The 20.0% and 15.9% of all new users in first and second year interrupted ibrutinib. The total integrated cost of FL patients was €55,732 reducing by about €15,000, while it was €58,716 for SLL ones decreasing by €6,000, respectively, in the first and in the second year. Pharmaceuticals were the key cost driver (ibrutinib accounted for more than 77%).

conclusionsThis analysis on Italian administrative data provided results about prescription patterns of ibrutinib FL and SLL new users with CLL, focusing on discontinuation, treatment change and healthcare costs over 2-year follow-up, and contributed to improve the knowledge on this hard-to-treat disease.