Novartis announced that the US Food and Drug Administration (FDA) has accepted the company's supplemental New Drug Application (sNDA) and granted Priority Review designation to Promacta (eltrombopag) in combination with standard immuno suppressive therapy (IST) for first-line treatment of severe a plastic anemia (SAA).

Promacta, which is marketed as Revolade in most countries outside the US, is an oral thrombopoietin receptor agonist (TPO-RA) that is already approved for SAA in the refractory setting for patients who have had an insufficient response to IST. It is also approved for adults and children with chronic immune thrombocytopenia (ITP) for patients who are refractory to other treatments and for the treatment of thrombocytopenia in patients with chronic hepatitis C virus (HCV) infection.

"Promacta is a great example of our drive to develop innovative treatments in serious disease areas where few treatment options exist," said Samit Hirawat, MD, Head, Novartis Oncology Global Drug Development. "Thanks to the many individuals and organizations who have helped us to advance the development of this promising medicine. We will continue our work with the FDA to make Promacta available for this potential new indication as quickly as possible."

The Priority Review for first-line SAA is based on Novartis' analysis of research sponsored by the Intramural Research Program of the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH) and conducted under a Cooperative Research and Development Agreement (CRADA). The study showed that more than half (52%) of treatment-naïve SAA patients achieved complete response at six months when treated with Promacta concurrently with standard IST, which was an increase of 35% compared to those treated with the standard IST alone. The overall response rate was 85% at six months.

Severe aplastic anemia is a rare, life-threatening, acquired blood disorder in which a patient's bone marrow fails to produce enough red blood cells, white blood cells and platelets. As a result, people living with this serious disease may experience debilitating symptoms and complications, such as fatigue, trouble breathing, recurring infections and abnormal bruising or bleeding that can limit their daily activities. Historically, SAA was nearly uniformly a fatal diagnosis due to infection or hemorrhage resulting from prolonged pancytopenia; untreated SAA can result in 80-90% mortality in 1-2 years The prevalence rates vary for aplastic anemia in the US, but it is believed that 500-1,000 new cases are diagnosed each year. The standard treatment regimen for individuals unable to receive or not eligible candidates for hematopoietic stem cell transplantation (HSCT) in the US for treatment-naïve SAA is IST. With IST as first-line treatment, up to one-third of patients and approximately 40% of those unresponsive to IST die within 5 years of diagnosis.

According to FDA guidelines, treatments that receive Priority Review designation are those that address a serious or life threatening disease or condition and, if approved, would provide a significant improvement in treatment safety or efficacy. If a treatment is granted Priority Review designation, the goal of the FDA is to issue a decision within six months of application submission, rather than ten months for standard review.
 
Eltrombopag, marketed as Promacta in the US and Revolade in countries outside the US, is approved in more than 100 countries worldwide for the treatment of thrombocytopenia in adult patients with chronic immune (idiopathic) thrombocytopenic purpura (ITP) who have had an inadequate response or are intolerant to other treatments, approved in over 45 countries worldwide for the treatment of patients with severe aplastic anemia (SAA) who are refractory to other treatments, and also approved in more than 50 countries for the treatment of thrombocytopenia in patients with chronic hepatitis C to allow them to initiate and maintain interferon-based therapy. Promacta/Revolade is approved in the US and in the European Union for the treatment of thrombocytopenia in pediatric patients 1 year and older with chronic immune (idiopathic) thrombocytopenia (ITP) who have had an insufficient response to corticosteroids and immunoglobulins.