The low platelet treatment is now approved for use in a combination therapy for severe aplastic anemia.

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. Symptoms include fatigue, trouble breathing, recurring infections, and abnormal bruising or bleeding. Standard immunosuppressive therapy is not always effective. 

Promacta (eltrombopag), marketed in most countries outside the US as Revolade, was previously approved for the treatment of patients with the blood disorder severe aplastic anemia (SAA) who have had an insufficient response to standard immunosuppressive therapy (IST). It is also already approved for the treatment of adults and children with chronic immune thrombocytopenia (ITP) who are refractory to other treatments, and for the treatment of thrombocytopenia in patients with chronic hepatitis C virus (HCV) infection. 

Recently, the US Food and Drug Administration (FDA) expanded its approval of Promacta to include first-line treatment of for adults and pediatric patients two years and older with SAA in combination with standard IST. According to developer Novartis, Promacta is the first new treatment in decades for newly diagnosed SAA patients in the US. The European Medicines Agency is expected to approve the drug for this use in 2019. 

The approval by FDA was based on the results of a clinical study sponsored by the National Heart, Lung and Blood Institute (NHLBI) Division of Intramural Research Program and conducted under a Cooperative Research and Development Agreement (CRADA).

The FDA also granted a Breakthrough Therapy designation to Promacta for treatment of patients with low platelet counts following exposure to radiation [hematopoietic sub-syndrome of acute radiation syndrome (H-ARS)]. Promacta has been shown to decrease the risk of hemorrhage in patients with radiation sickness. Novartis is pursuing the development of Promacta for H-ARS under contract with the US Department of Health and Human Services' Biomedical Advanced Research and Development Authority (BARDA) for potential use following deliberate, natural, and emerging radio/nuclear threats.