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 for patients who have had an insufficient response to IST.
It is also approved for 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.
Novartis Oncology CEO Liz Barrett said: “Severe aplastic anemia can be a fatal diagnosis if left untreated, and many patients fail to respond to current initial treatment options.
“Today’s US approval for Promacta is an important step forward for people living with this challenging disease and shows how Novartis continues to reimagine care in areas where few treatment options exist.”
The FDA’s approval is based on Novartis’ analysis of research 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 study showed that 44% (95% CI 33, 55) of definitive IST-naive SAA patients achieved complete response at 6 months when treated with Promacta concurrently with standard IST, which was 27% higher than the complete response rate historically observed with the standard IST alone[1]. The overall response rate was 79% (95% CI 69, 87) at 6 months.
These high response rates have a significant clinical impact for patients with SAA who were not previously treated with standard IST.
These results further build on the IST-refractory indication for patients with SAA which Promacta was granted in 2015, in which a subset of patients maintained stable counts and demonstrated restoration of bone marrow function following Promacta discontinuation.
The new data in IST-naïve SAA includes sustained response with a median duration of response of 24.3 months for patients receiving 6 months of Promacta in combination with horse anti-thymocyte globulin (h-ATG) and cyclosporine (CsA) followed by maintenance CsA4.
In this study, the most common adverse reactions reported (incidence >=5%) were abnormal liver function tests, rash, and skin discoloration including hyperpigmentation.
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[5]. 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 the body’s inability to produce new blood cells.
“Patients with SAA sometimes do not respond to the current treatment standard of IST,” said Phillip Scheinberg, MD, Head, Division of Hematology, Hospital A Beneficência Portuguesa de São Paulo in Brazil, and previously with the Hematology Branch of the NHLBI.
“With this approval, physicians now have an option to add Promacta to the standard IST in a regimen that has demonstrated significant overall and complete response rates upfront in SAA and reduce the numbers of those who are unresponsive to initial therapy.”
Novartis submitted a Type II variation application for Revolade as a first-line SAA treatment to the European Medicines Agency in April 2018 and is expecting a decision in 2019.
The FDA also granted Promacta Breakthrough Therapy designation as a counter measure for hematopoietic sub-syndrome of acute radiation syndrome (H-ARS).
Acute radiation syndrome, also known as radiation sickness, occurs after exposure to ionizing radiation and leads to many symptoms including thrombocytopenia. Thrombocytopenia is a reduction in platelet counts that increases the risk of hemorrhage[6]. Promacta was shown to decrease the risk of hemorrhage in patients with radiation sickness.
Research and development of Promacta for H-ARS is being conducted 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, specifically to treat patients exposed to myelosuppressive doses of radiation.
FDA Breakthrough Therapy designation is for medicines that treat a serious or life-threatening disease or condition, and demonstrate a substantial improvement over existing therapies on one or more clinically significant endpoint based on preliminary clinical evidence.
Eltrombopag, marketed as Promacta in the US and Revolade in countries outside the US, is approved in more than 90 countries worldwide for the treatment of thrombocytopenia in adult patients with chronic immune thrombocytopenic purpura (ITP) who have had an inadequate response or are intolerant to other treatments.
It is also approved for the treatment of patients with severe aplastic anemia (SAA) as first-line therapy in the US (patients 2 years and older) and Japan, and in many other countries for patients who are refractory to other treatments.
In more than 40 countries, Promacta/Revolade is indicate 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 thrombocytopenia (ITP) who have had an insufficient response to corticosteroids, immunoglobulins, or splenectomy.
Promacta should only be used in patients with ITP whose degree of thrombocytopenia and clinical condition increase the risk for bleeding.
Source: Company Press Release