GlaxoSmithKlineGlaxoSmithKline announced that the United States Food and Drug Administration (FDA) has granted Priority Review for Promacta®/Revolade® (eltrombopag) for the short-term treatment of patients with chronic idiopathic thrombocytopenic purpura (ITP). Eltrombopag is an investigational, once-daily oral treatment that induces the production of cells in the bone marrow to generate platelets, which are critical in minimising the incidence of bleeding in chronic ITP.

If approved, eltrombopag would be the first oral thrombopoeitin (TPO) receptor agonist for the short-term treatment of previously treated patients with chronic ITP to increase platelet counts and reduce bleeding.

"Our goal for eltrombopag is to make available a targeted therapy in oral form for patients to help raise their platelet counts without having to suppress the immune system," said Paolo Paoletti, M.D., Senior Vice President of the Oncology Medicine Development Center at GSK. "The FDA designation of our submission for priority review is very encouraging and brings us closer to offering physicians and their patients eltrombopag."

The priority review designation means FDA is expected to make a decision on the NDA for the investigational compound within six months of the submission.

In pivotal studies, the most common adverse events observed in patients taking eltrombopag were headache, nausea, nasopharyngitis, diarrhoea and vomiting.

GSK also plans to submit a Marketing Authorisation Application (MAA) for eltrombopag in the treatment of chronic ITP in Europe in 2008 where it will be marketed as Revolade®. The compound is also being studied for long-term treatment of chronic ITP, as well as thrombocytopenia associated with Hepatitis C Virus cirrhosis and chemotherapy induced thrombocytopenia.

About ITP
Chronic ITP is a disorder marked by increased platelet destruction and/or inadequate platelet production in the blood, which causes an increased risk of bruising and bleeding.[1,2] There are estimated to be approximately 60,000 individuals diagnosed with chronic ITP in the U.S.[3] and a similar number in Europe. People with chronic ITP often bleed from small blood vessels causing bruises, nosebleeds or even fatal gastrointestinal or intra cerebral bleeds, although these are rare.[1]

About Eltrombopag
Eltrombopag is an oral, non-peptide thrombopoietin receptor agonist that has been shown in pre-clinical research and clinical trials to stimulate the proliferation and differentiation of megakaryocytes, the bone marrow cells that give rise to blood platelets. Eltrombopag was discovered as a result of research collaboration between GlaxoSmithKline and Ligand Pharmaceuticals (NASDAQ: LGND). It is being developed by GlaxoSmithKline. Eltrombopag is an investigational compound that has not received regulatory approval in any market for any indication at this time.

About GlaxoSmithKline
GlaxoSmithKline – one of the world's leading research-based pharmaceutical and healthcare companies – is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For company information, visit GlaxoSmithKline at www.gsk.com.

Revolade® and Promacta® are registered trademarks of the GlaxoSmithKline group of companies
Promacta® is the proposed registered trademark to be used in the United States
Revolade® is the proposed trade mark for use in certain European countries

References:
1. National Heart, Lung, and Blood Institute. Diseases and Conditions Index. www.nhlbi.nih.gov/health/dci/Diseases/Itp/ITP_WhatIs.html. Accessed November 12, 2007.
2. Cines DB, Blanchette V. Idiopathic thrombocytopenic purpura. N Engl J Med. 2002;364: 995-1008.
3. Feudjo-Tepie M, Robinson N, Bennett D. Prevalence estimates of adult chronic idiopathic thrombocytopenic purpura (ITP). J Thromb Haemost. 2008 doi: 10.1111/j.1538-7836.2008.02911.x.