Novel thrombopoietic agents: a review of their use in idiopathic thrombocytopenic purpura

Roberto Stasi, Maria L Evangelista, Sergio Amadori
Drugs 2008, 68 (7): 901-12
The underlying problem in idiopathic thrombocytopenic purpura (ITP) has traditionally been recognized as accelerated platelet destruction. However, recent studies have provided evidence that the pathophysiology of ITP is more complex, and impaired platelet production has emerged as one of the mechanisms contributing to the thrombocytopenia. On these grounds, second-generation thrombopoietic agents have been used in clinical trials to stimulate platelet production in ITP patients who are not responsive to standard treatments. These new molecules bear no structural resemblance to thrombopoietin (TPO) but still bind and activate the TPO receptor. Studies have been completed for two TPO receptor agonists: romiplostim (formerly AMG 531) and eltrombopag (formerly SB497115). Romiplostim is a recombinant protein defined as a peptibody. Results of phase I-II trials published recently demonstrated that romiplostim given as a weekly subcutaneous injection for 1-6 weeks results in doubling of platelet counts and an increase to >50 x 10(9)/L in most treated patients with minimal adverse effects. Eltrombopag is an orally available, small organic compound. In a randomized, double-blind, placebo-controlled phase III trial, ITP patients were given daily oral treatment with placebo or eltrombopag 50 mg. Platelet responses were observed in 59% of eltrombopag-treated patients and in 16% of patients in the placebo arm. No significant adverse events were seen. Other thrombopoietic agents in development, such as AKR-501 (formerly YM 477), appear promising in healthy volunteers. Ongoing phase III clinical trials will reveal the potential of these agents in the management of ITP prior to splenectomy and for long-term maintenance therapy, as well as their relative benefit compared with standard of care treatment.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"