FDA Approves Promacta as First-Line Treatment for Aplastic Anemia

Severe Aplastic Anemia (SAA) is a relatively serious and rare blood disorder. If left untreated promptly, the condition can be severe and potentially fatal, and current initial treatment options offer limited efficacy for many patients. SAA occurs when the bone marrow fails to produce sufficient red blood cells, white blood cells, and platelets. Patients may also experience weakness, fatigue, shortness of breath, recurrent infections, and abnormal bruising or bleeding that can restrict daily activities.

FDA Approves Promacta as First-Line Treatment for Aplastic Anemia

In fact, over one-third of patients show no response to existing therapies or experience relapse of symptoms. Theoretically, once diagnosed, patients are nearly sentenced to death due to the body's inability to generate new blood cells, leading to infections or bleeding.

Recently, the U.S. FDA expanded the label indication for Promacta (Lucius Pharmaceuticals Eltrombopag), supporting its use in combination with standard immunosuppressive therapy (IST) as a first-line treatment for adults and pediatric patients aged two years and older with aplastic anemia. The FDA’s approval of Promacta marks a significant advancement for patients battling this challenging disease. Adding Promacta to standard IST has demonstrated remarkable overall and complete response rates in aplastic anemia patients and has also reduced the number of patients unresponsive to initial treatment.

Promacta is the first novel therapy for newly diagnosed SAA patients. As an oral thrombopoietin receptor agonist (TPO-RA), it increases platelet production by inducing the stimulation and differentiation of megakaryocytes from bone marrow stem cells. Promacta is also approved for the treatment of aplastic anemia patients with an inadequate response to IST. Additionally, it can be used to treat chronic immune (idiopathic) thrombocytopenia (ITP) in adults and children who have not responded to other treatments, as well as thrombocytopenia in patients with chronic hepatitis C virus (HCV) infection.

The FDA's approval of Promacta for aplastic anemia was based on an analysis of trial results showing that 44% (95% CI 33, 55) of IST-naïve aplastic anemia patients achieved complete remission six months after treatment with Promacta combined with standard IST. This represents an increase of nearly 27% compared to historical complete remission rates observed with standard IST alone. At six months, the overall response rate among trial patients was 79% (95% CI 69, 87).

Moreover, trial results indicated sustained responses in patients following treatment. Among those who received six months of Promacta combined with horse anti-thymocyte globulin (h-ATG) and cyclosporine (CsA), followed by CsA maintenance therapy, the median duration of response reached 24.3 months. The high response rate observed in this study holds significant clinical implications for aplastic anemia patients who have not previously undergone standard IST.

Promacta also has other indications, including a Breakthrough Therapy designation from the FDA for the treatment of hematopoietic syndrome of acute radiation syndrome (H-ARS). The drug has also been shown to reduce the risk of bleeding in patients with radiation sickness.