Comparison of treatment characteristics between patients diagnosed with immune thrombocytopenia (ITP) and treated with thrombopoietin receptor agonists (TPO-RA).

e18314 Background: There is limited real-world information on the utilization of TPO-RAs, eltrombopag (ELT) and romiplostim (ROM), for the treatment of ITP. Methods: The study employed a retrospective, longitudinal cohort design using integrated healthcare claims data from July 2008-June 2015. Adults diagnosed with ITP initiating TPO-RA therapy from Jan 2009-July 2014 were included. Patients not continuously enrolled in benefits for 6-months prior and 12-months post the index date (first TPO-RA claim date) were excluded. Index TPO-RA discontinuation rates, concomitant therapy, restarts, subsequent therapy, and treatment free periods were assessed. Results: Of the 1,067 patients included, 26.5% (283) received ELT and 73.4% (784) ROM. Age (58.8 vs 59.3; P= 0.705) and gender (males: 45.9% vs 46.6%; P= 0.858) were similar between cohorts. Among ELT and ROM patients 35.7% and 27.6% continued therapy (no gap of ≥30 days) for ≥1 year ( P= 0.010). The average duration of continuous therapy (up to gap ≥30 days) was 131 and 108 days, respectively ( P= 0.001). During continuous course of index TPO-RA treatment 52.7% ELT and 47.2% ROM patients received concomitant ITP-related treatment ( P= 0.115). Following discontinuation, 42.9% of ELT patients restarted ELT, 22.0% did not initiate any subsequent ITP treatments, and 35.2% started a new ITP treatment. Among patients who discontinued ROM, 38.4% restarted, 26.9% did not receive any subsequent therapy, and 34.7% initiated a new treatment. Treatment free periods (≥30 days with no ITP treatment) were experienced by 52.7% of ELT patients and 61.6% ROM patients ( P= 0.009). Mean duration of treatment free period was 109 and 137 days ( P< 0.001), respectively. Conclusions: ITP patients receiving ELT had a longer duration of treatment and shorter treatment free periods compared to patients receiving ROM. Further research is needed to compare clinical outcomes (e.g., platelet counts, bleeding symptoms and remissions) among ITP patients receiving ELT and ROM, in the real-world setting.