Safety of the thrombopoiesis-stimulating agents for the treatment of immune thrombocytopenia.

The thrombopoiesis-stimulating agents (TSAs) are a novel class of drugs for the treatment of chronic immune thrombocytopenia (ITP). Roimplostim and eltrombopag, the first two TSAs to enter clinical use, received regulatory approval in 2008 and stand poised to change the treatment paradigm in ITP. However, important questions regarding the safety of these agents, particularly with long-term use, remain partially unanswered. The primary objective of this article is to review the reported toxicities associated with the TSAs including rebound thrombocytopenia, thrombosis, hepatotoxicity, formation of neutralizing antibodies, bone marrow fibrosis, hematologic malignancy, cataract formation, and common adverse events. The incidence and severity of these toxicities as well as strategies for monitoring patient safety and pharmacovigilance are discussed.