Immune (idiopathic) thrombocytopenic purpura (ITP) treatment pattern and clinical efficacy

Abstract

17529 Background: Immune (Idiopathic) Thrombocytopenic Purpura (ITP) is an autoimmune disorder characterized by persistent thrombocytopenia (peripheral blood platelet count <150 × 109/L). Few studies report efficacy of current therapies for ITP or resulting health-related quality of life (HRQoL). We present interim results of an international multi-center prospective observational study describing clinical efficacy of ITP treatments (trts). Methods: Patients (pts) with a diagnosis (dx) of ITP from community and academic centers were enrolled. Pts retrospective chart data provided date of 1st ITP dx, trts received and medical history. ITP trts, dose, response, and duration of response were collected prospectively for 12 months (mo). HRQoL was assessed with an ITP questionnaire (ITP-PAQ) where higher scores relate to better patient-reported outcomes. Results: Of the first 100 pts (43% male and mean age 70 years), 24 received a splenectomy and 74 received ITP-related trts. Among the 74 pts, corticosteroids (N=61), intravenous immunoglobulins (IVIG) (N=36), rituximab (N=27), and anti-D antibody (N=22) were the most frequently used. On average, pts received 2 to 3 types of ITP trts during the study period (median person years=2.97) with corticosteroids usually as 1st line of treatment. Median duration of response was 8 mo for rituximab, 10 mo for corticosteroids, 15 mo for IVIG and 17 mo for anti-D antibody. Hospitalizations per person year ranged from 0 (rituximab) to 0.8 (IVIG). ITP-PAQ scores significantly decreased in pts on corticosteroids (p<0.05), compared to other trt groups where ITP-PAQ scores increased. Conclusions: Efficacy of all ITP trts was limited in duration and pts receiving corticosteroids had significantly decreased HRQoL. Further studies are needed to assess the long-term impact of ITP trts on patient outcomes, health resource utilization, and downstream costs. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Amgen, Inc. Amgen, Inc. Amgen, Inc.