Real-world use of thrombopoietin receptor agonists for the management of immune thrombocytopenia in adult patients in the United Kingdom: results from the TRAIT study

Few studies have reported the real-world use of both romiplostim and eltrombopag in immune thrombocytopenia (ITP). TRAIT was a retrospective observational study aimed to evaluate the platelet responses and adverse effects associated with the use of these thrombopoietin receptor agonists (TPO-RAs) in adult patients with ITP in the United Kingdom. Of 267 patients (median age at diagnosis, 48 years) with ITP (primary ITP [n = 218], secondary ITP [n = 49]) included in the study, 112 (42%) received eltrombopag and 155 (58%) received romiplostim as the first prescribed TPO-RA. A platelet count ≥30 × 10⁹/L was achieved in 89% of patients with the first TPO-RA treatments, while 68% achieved a platelet count ≥100 × 10⁹/L. Treatment-free response (TFR; platelet count ≥30 × 10⁹/L, 3 months after discontinuing treatment) was achieved by 18% of the total patients. Overall, 61 patients (23%) switched TPO-RAs, most of whom achieved platelet counts ≥30 × 10⁹/L with the second TPO-RA (23/25 who switched from eltrombopag to romiplostim [92%]; 28/36 who switched from romiplostim to eltrombopag [78%]). TFR was associated with secondary ITP, early TPO-RA initiation after diagnosis, the presence of comorbidity and no prior splenectomy or treatment with steroids or mycophenolate mofetil. Both TPO-RAs had similar efficacy and safety profiles to those reported in clinical studies.