GlaxoSmithKline is initiating Phase III trials of its investigational drug, eltrombopag, giving fresh hope to patients suffering from idiopathic thrombocytopenic purpura (ITP), a low platelet count disorder that leaves sufferers at risk of spontaneous bruising, mucosal bleeding and, in severe cases, intracranial hemorrhage.

The trial will investigate the drug's safety and efficacy in a double-blind, randomised, placebo-controlled, parallel group of 50 patients with previously-treated ITP. Sites for this multicentre study will involve 33 countries, including the US, UK, Canada and France.

Paolo Paoletti, managing director and senior vice president of GlaxoSmithKline’s Oncology Medicine Development Centre, said: “Data to date demonstrates that eltrombopag may be effective in increasing platelet counts in patients with chronic ITP and this trial will help us to further evaluate its potential.”

Ph II results promising

Top-line results of the Phase II trial in ITP were reported in December 2005. These showed that eltrombopag, at doses of 75mg and 50mg, increased platelet count from a baseline of less than 30,000/L to at least 50,000/L after 42 days of dosing.

ITP is thought to affect between 50 and 100 people per million in the US and Europe. Although the disease can be managed chronically, as many as 5% of patients die within ten years of diagnosis. The condition can also impede a variety of medical treatments, in particular chemotherapy, and interferon therapy for patients with hepatitis C infection, by preventing patients from receiving their full dose.