P1523: demographics, clinical characteristics, and real-world treatment patterns among patients with beta-thalassemia: a retrospective medical record abstraction study

Background: Beta-thalassemias (BTs) are genetic disorders of hemoglobin (Hb) synthesis defined by deficient or absent synthesis of the beta-globin subunit. As a result, patients with BT experience hypochromic anemia and excess alpha-globin chain, causing ineffective erythropoiesis and low-grade hemolysis; however, patient characteristics and treatment patterns are not well understood. Aims: This retrospective medical record abstraction study evaluated patients prior to introduction of luspatercept with transfusion-dependent (TD) and non-transfusion-dependent (NTD) BT for demographics, clinical characteristics, and treatment patterns. Methods: Medical records of adults with TD or NTD BT in the United Kingdom (UK), France, Germany, Spain, and Canada with ≥5 years of visit history within the practice were evaluated. The target sample size was 50 patients in all countries (except Canada: N=20 patients), with an even distribution of patients with TD and NTD BT. Information on demographics, clinical characteristics, and treatment patterns was abstracted from the medical records. Results: In total, 118 patients with TD and 96 patients with NTD BT were identified. Among patients with TD BT, mean (standard deviation [SD]) patient age was 36.1 (11.9) years, and 28.8% were female; among patients with NTD BT, mean (SD) patient age was 36.6 (9.8) years, and 38.5% were female (Table). Table shows characteristics and results per country. Among patients with TD BT, 90/118 (76.3%) were receiving transfusions at least once every 4 weeks, with 5.1% receiving transfusions weekly, 16.1% every 2 weeks, 28.8% every 3 weeks, 26.3% every 4 weeks, 3.4% every 5 weeks, 17.8% every 6 weeks, and 2.5% other or unknown. Patients with TD BT had an average (SD) of 2.4 (0.6) units of blood transfused per session (range, 1.9 in Spain to 2.7 in UK), with an average (SD) Hb level before the transfusion of 6.9 (1.3) g/dL (range, 5.9 in Canada to 7.3 in Germany). Patients with TD BT had been on the transfusion regimen for an average of 72.6 months (range, 45.2 in Canada to 104.9 in UK) during the observation period. All patients with NTD BT had previously had ≥1 transfusion at any point in time that the physician was aware of, with an average (SD) of 2.9 (0.9) transfusions per patient (range, 2.6 in Canada to 3.1 in Germany). Among patients with NTD BT with detailed transfusion data available post-index date (N=81; 84.4%), the mean (SD) number of units of blood per transfusion was 2.2 (0.6) (range, 1.9 in Spain to 2.7 in France), and the mean (SD) Hb level before transfusion was 7.4 (1.2) g/dL (range, 6.2 in Canada to 8.2 in Spain). Iron chelation therapy was received in 70.3% of TD patients (range, 44.4% in the UK and 92.6% in Germany) and in 45.8% of NTD patients (range, 37.0% in France to 80.0% in Canada). The percentages of patients with hepatitis B, C, and D were low (ie, all <2%) for both the TD and NTD cohorts, as were the percentages of patients with cerebrovascular disease (2.5% for TD and 1.0% for NTD) and congestive heart failure (5.1% for TD and 2.1% for NTD). Image:Summary/Conclusion: Real-world data on clinical practice and outcomes in patients with BT are lacking. This study found that NTD and TD patients with BT have similarly low pre-transfusion Hb levels. A high number of patients, especially TD patients, are not treated according to the current recommendations, highlighting the importance of national reference centers to improve outcomes and quality of life in these patients.