GSK/Ligand Promacta win FDA priority review in severe aplastic anemia
This article was originally published in Scrip
GlaxoSmithKline won a priority review from the FDA for Promacta (eltrombopag) as a treatment for cytopenias in patients with severe aplastic anemia (SAA) who have had insufficient response to immunosuppressive therapy (IST).
The good news, however, didn't much help GSK's partner Ligand Pharmaceuticals, whose shares rose 2% only to fall 4.7%, before closing at $63.17, down $2.65, or 4% on 30 April.
Promacta, a thrombopoietin receptor agonist, already is approved in the US to treat thrombocytopenia in patients with chronic immune thrombocytopenia who have had an insufficient response to
corticosteroids, immunoglobulins or splenectomy.
The drug also is approved as a therapy for thrombocytopenia in patients with chronic hepatitis C to allow the initiation and maintenance of interferon-based therapy.
The companies did not reveal a Prescription Drug User Fee Act action date for Promacta in SAA, but the priority review means GSK could have a decision within six-to-eight months for the drug in SAA, a rare disorder in which the bone marrow fails to make enough new blood cells.
There currently are no drugs approved in the US for SAA for patients unresponsive to initial immunosuppressive therapy – a population in which 40% die from infection or bleeding within five years of their diagnosis.
The FDA in February deemed Promacta in the SAA indication as a breakthrough therapy, a status intended to expedite the regulatory process (scripintelligence.com, 3 February 2014).
The supplemental new drug application for Promacta in SAA was based on the results from an open-label, Phase II National Institute of Health study (09-H-0154) of the drug in 43 heavily pre-treated SAA patients with an insufficient response to IST.
Shares of GSK closed at $55.37 on 30 April, down $1.02, or 1.8%.