A further study reveals improved treatment tolerability as the most important unmet medical need in chronic ITP

Not for distribution to US Media

Issued: Sunday 15 June 2008, London, UK

GlaxoSmithKline today announced data on the long-term safety and efficacy of its investigational drug Revolade^® (eltrombopag) for the treatment of chronic idiopathic thrombocytopenic purpura (ITP). ^[1] Results from the ongoing, open label EXTEND (Eltrombopag eXTENded Dosing) (Abstract 0949) study showed that 80% of patients achieved a platelet count of >50,000/µL at least once and 78% of these patients maintained platelets >50,000/µL for over 50% of their time in the study. These results suggest that eltrombopag sustains increased platelet counts during long-term treatment.¹ Chronic ITP is a disorder characterised by low platelet levels which can result in excessive bruising and bleeding. ^[2] This research was presented at the 13th congress of the European Hematology Association, 12-15 June 2008, Copenhagen, Denmark.

In the trial, eltrombopag was well tolerated with no evidence of loss of efficacy. Eighty five patients (78%) reported at least one adverse event (AE) on-therapy; the majority of which were mild to moderate, headache being the most common (17%). There were two deaths unrelated to eltrombopag.¹ To date, 109 patients in this study have received eltrombopag and median duration in the study was 194 days. Eltrombopag, an oral, non-peptide thrombopoietin receptor agonist, was initiated at 50mg daily and then the dose was adjusted according to the platelet count, with doses between 25mg and 75mg daily.

"Current approaches to increase platelet count typically include treatment with corticosteroids or intravenous immunoglobulin injections, both of which have issues with tolerability, such as weight gain, osteoporosis, hypertension and intense headaches. Many patients can also stop responding to these treatments and relapse,” said Roberto Stasi, M.D., Department of Medical Sciences, Regina Apostolorum Hospital, Albano Laziale, Italy. "These long-term efficacy and safety results are encouraging and suggest that eltrombopag, once approved, may provide physicians with a new treatment option to conveniently raise and maintain patients' platelet levels and alleviate their ITP symptoms."

A further study (Abstract 0431), also presented at this meeting, confirmed the need for improved treatment tolerability in chronic ITP. Outcomes from The Burden of Chronic ITP in Adults: Results of a Delphi Panel of 32 European Clinical Experts reported that 88% of experts surveyed cited improved treatment tolerability as the most important unmet medical need in chronic ITP due to the poor side effect profile of current treatments. The greatest impact of chronic ITP on patients in terms of health-related quality of life (HRQoL) was perceived by 66% of experts to be patients’ fear of bleeding followed closely by treatment side effects (60% of experts). ^[3]

This study is part of a comprehensive project investigating the burden of chronic ITP, which involves both expert opinion and actual patient data. Thirty-two haematologists/oncologists at treatment centres with large ITP patient populations in France, Germany, Italy, Spain and the UK participated in the study. This study provided some of the first insights into current ITP treatment practices and perceptions across Europe.³

Further eltrombopag data presented, for the first time, at the meeting showed that treatment with eltrombopag provided consistent and predictable platelet responses and was well tolerated upon repeated administration. In the REPEAT trial (Repeat ExPosure to Eltrombopag in Adults with Idiopathic Thrombocytopenic Purpura) (Abstract 0294) repeated intermittent use of eltrombopag produced consistent and predictable responses in patients with chronic ITP, generating similar platelet counts with each subsequent cycle. A decrease in bleeding was also observed in each on-therapy period vs. baseline. Eltrombopag was administered to 66 patients with baseline platelet counts of 20,000 – 50,000/µL across three cycles of treatment. A cycle consisted of an on-therapy period of up to six weeks, followed by an off-therapy period of up to four weeks. Only patients responding (defined as platelets ³50K/mL and 2x baseline) in cycle one were allowed to continue with cycle two or three. Eighty-two percent of patients responded in cycle one, with 88% achieving the primary endpoint (consistency of response in cycle two or three, given response in cycle one). There were no serious adverse events reported and headache was the most frequently reported adverse event (17%). ^[4] The REPEAT study is an ongoing trial.

“We are extremely encouraged by the continued progress in our eltrombopag clinical development programme”, said Dr Michael Arning, Group Medical Director, Oncology Medicine Development Centre, GSK. “We continue to be very optimistic about eltrombopag. Our ongoing efforts to assess the benefits of both short- and long-term eltrombopag treatment of ITP will be part of GSK’s commitment to providing patients with a convenient, effective and well tolerated ITP treatment.”

About Chronic ITP

Chronic ITP is a disorder characterised by low levels of platelets in the blood, with patients suffering from excessive bruising and bleeding and in some cases having serious hemorrhages that can be fatal. ^2,[5],[6] There are estimated to be approximately 60,000 individuals diagnosed with chronic ITP in the U.S ^[7] and a similar figure in EU. Although ITP can be managed chronically, it is associated with significant mortality and morbidity. The predicted five year mortality is between 2% for young patients and 48% for older patients. The risk of fatal hemorrhage is estimated to be 1.2% for 40-60 year olds and 13% for the over 60’s. ^[8]

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. ^[9] The efficacy and safety profile will be further examined in ongoing clinical trials. Eltrombopag was discovered as a result of research collaboration between GlaxoSmithKline and Ligand Pharmaceuticals. 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 is one of the world’s leading research-based pharmaceutical and healthcare companies. GlaxoSmithKline is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For company information visit www.gsk.com.

Notes to editors

Revolade® and Promacta® are registered trade marks 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.

To access the latest GSK Oncology media materials, visit www.gskcancermedia.com

Enquiries:

 

UK Media enquiries:	Philip Thomson	(020) 8047 5502
	Alice Hunt	(020) 8047 5502
	Gwenan White	(020) 8047 5502
	Claire Brough	(020) 8047 5502
European Analyst/Investor enquiries:	David Mawdsley	(020) 8047 5564
	Sally Ferguson	(020) 8047 5543
	Gary Davies	(020) 8047 5503

References