Drug-based on MGH discovery may significantly improve treatment of dangerous bloo...( Two clinical trials of the novel dru...),Health

Two clinical trials of the novel drug romiplostim (Nplate) show that it significantly improved platelet levels in patients with chronic immune thrombocytopenic purpura (ITP), a hematologic disorder that can cause uncontrolled bleeding. An international research team reports Phase 3 trial results for the drug, which duplicates the action of a natural hormone discovered by a Massachusetts General Hospital (MGH) investigator, in the February 2 issue of The Lancet.

Many ITP patients have had to choose between no therapy or a treatment with limited efficacy and potentially serious side effects, says David Kuter, MD, DrPhil, director of Clinical Hematology at MGH and lead author of the Lancet study. The low toxicity and high response to this drug may convert a potentially life-threatening condition to one that can be easily managed with a weekly injection.

ITP is a chronic disorder in which the immune system destroys platelets, blood cells that help prevent bleeding. While some ITP patients experience only increased bruising, others may have serious bleeding and occasionally dangerous hemorrhage. Recent investigations suggest that, in addition to the destruction of existing platelets, ITP also may be due to reduced platelet production. Currently available treatments for ITP including steroid drugs, which have significant side effects, and removal of the spleen (splenectomy) are designed to reduce platelet destruction and may be ineffective in many patients.

Thrombopoietin is the natural regulator of platelet production. Kuter was one of the original discoverers of the hormone in 1994 and has been active in developing thrombopoietic drugs ever since. Romiplostim is a unique peptibody a peptide antibody that stimulates platelet production by mimicking the action of thrombopoietin. Earlier Phase 1 and 2 trials have shown that romiplostim increases platelet production in healthy volunteers and in short-term treatment of ITP pat
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