Treatment characteristics, efficacy and safety of thrombopoietin analogues in routine management of primary immune thrombocytopenia

Thrombopoietin receptor agonist (TPO-RAs) have demonstrated good efficacy and tolerance in clinical trials in refractory chronic primary immune thrombocytopenia (ITP) or chronic ITP with contraindication for splenectomy. No head-to-head study is available, and differences in trials design do not allow comparisons. Information on the use of TPO-RAs in nonchronic ITP is scant. We described our experience with TPO-RAs in ITP (chronic, persistent and newly diagnosed ITP) in routine clinical practice. Retrospective series of 100 adult ITP patients was analysed; 41 treated with eltrombopag, 37 with romiplostim and 22 with both. Response-related and safety variables were evaluated. With a median follow-up of 86.5 weeks (interquartile range, 34.3-128 weeks), no differences were found in response rate, time to response, stability of response or response duration based on the type of TPO-RA used. Of all, 25% of patients with newly diagnosed or persistent ITP and 7.2% with chronic responded and maintained their response when TPO-RAs were stopped. Regarding safety, two developed bone marrow fibrosis grade 3, with loss of response to both drugs. Incidence of vascular events was 7%. Both TPO-RAs may be useful in all types of ITP, not only chronic but also persistent and newly diagnosed. Similar results were noted in efficacy and safety variables for both drugs.