Treatment for rare bleeding disorder effective and well-tolerated, studies show

The results of two international studies carried out at dozens of trial centers worldwide show for the first time that eltrombopag is a safe and effective treatment for children with persistent or chronic immune thrombocytopenia – a rare bleeding disorder where the blood does not clot as it should, due to low numbers of blood platelets.

The findings are published in The Lancet and The Lancet Haematology.

Immune thrombocytopenia (ITP) is an autoimmune disorder where the immune system attacks blood platelets, depleting them to such an extent that it leads to bleeding inside the body and under the skin.

Four in every 100,000 children develop ITP each year globally.

Symptoms of ITP include frequent nosebleeds, bleeding from the gums and bruising that appears as purple patches or tiny red spots on the skin. In rare instances, the bleeding can be life-threatening.

ITP can sometimes go away by itself, but for around 1 in 4 children affected, the condition becomes chronic, persisting after initial treatment for at least 12 months.

One of the centers that participated in the studies is at Royal Manchester Children’s Hospital in the UK. The work there was led by Dr. John Grainger, consultant pediatric hematologist and honorary lecturer at The University of Manchester, who notes:

“The studies provide clinicians with much-needed evidence to help decide when eltrombopag would benefit paediatric patients and provide dosage regimens suitable for paediatric patients.”

In the past, second-line treatments for children with ITP were scarce, and one of the earliest options – to remove the spleen – carries a high risk of sepsis and thrombosis.

Eltrombopag increased and ‘consistently stabilized platelet count’
As researchers began to understand more about the underlying causes of ITP, immunosuppressant drugs like rituximab became available as new treatment options.

And more recently, thrombopoietin receptor agonists like eltrombopag have been approved for the treatment of thrombocytopenia in adult patients with chronic ITP who have either not responded or shown intolerance to other options.

Eltrombopag works by helping to trigger proliferation and differentiation of bone marrow stem cells to increase production of blood platelets.

Dr. Grainger sums up the results of the two studies:

“The studies demonstrate that eltrombopag is well tolerated and effective, consistently stabilising the platelet count to over 50 X 109 per litre within 2-6 weeks for 40% of children receiving the treatment, compared with 0% on the placebo arm.”
Eltrombopag is marketed as Promacta in the US and as Revolade in Europe and other countries across the world. As a result of these studies, US regulators have licensed the drug for use in children under the age of 1 year. EU licensing for this application is currently in progress.

The studies were funded by GlaxoSmithKline (GSK). However, eltrombopag is now manufactured and marketed by Novartis, following its recent purchase of GSK Oncology.