Eltrombopag: a thrombopoietin receptor agonist for idiopathic thrombocytopenic purpura.

OBJECTIVE:

To review the pharmacology, pharmacokinetics, safety, and efficacy of eltrombopag in previously treated patients with chronic idiopathic thrombocytopenic purpura (ITP).

DATA SOURCES:

Articles were identified through a search of the MEDLINE (1950DSDecember 2008) database for English-language articles containing the key words eltrombopag, SB-497115, idiopathic thrombocytopenic purpura, and immune thrombocytopenic purpura. References from publications identified in this search were reviewed for relevant information. Unpublished data received from the manufacturer was also included in this review. Study Selection and

DATA EXTRACTION:

All articles identified from the data search were reviewed for relevant information. Applicable information was included in this review.

DATA SYNTHESIS:

Eltrombopag is a new oral thrombopoietic receptor agonist approved by the FDA in November 2008 as second-line treatment of chronic ITP. It stimulates human megakaryocyte differentiation and proliferation, leading to increased platelet production. Eltrombopag has been shown in clinical trials to increase platelet counts in a dose-dependent manner regardless of splenectomy status, baseline platelet counts, and concurrent ITP therapy. Available data show a statistically significant decrease in the incidence of any bleeding (World Health Organization Grades 1DS4) and clinically significant bleeding (Grades 2DS4). Common adverse effects are mild and typically do not lead to treatment discontinuation. Results from clinical studies demonstrated significant increase in platelet counts with minimal adverse effects.

CONCLUSIONS:

Eltrombopag treatment provides a potential new resource for clinicians to use in the pharmacotherapy of ITP. Further studies are needed to explore its long-term safety and efficacy in patients with chronic ITP.