Rigel announced the U.S. Food and Drug Administration (FDA) approved Tavalisse (fostamatinib disodium hexahydrate) for the treatment of thrombocytopenia in adult patients with chronic immune thrombocytopenia (ITP) who have had an insufficient response to a previous treatment. Tavalisse is an oral spleen tyrosine kinase (SYK) inhibitor that targets the underlying autoimmune cause of the disease by impeding platelet destruction, providing an important new treatment option for adult patients with chronic ITP. Rigel plans to launch Tavalisse in the United States in late May 2018.
"Chronic ITP is challenging to treat because the heterogeneity of the disease makes it difficult to predict how an individual patient will respond to available treatments and not all patients can find a treatment that works well for them," said James Bussel, M.D., professor emeritus of pediatrics at Weill Cornell Medicine and the principal study investigator on the FIT Phase 3 program. Dr. Bussel has served as a consultant and paid member of the advisory board for Rigel Pharmaceuticals, Inc. "The FDA approval of fostamatinib arms physicians with a new treatment option, which works via a novel mechanism."
The FDA approval of Tavalisse was supported by data from the FIT clinical program, which included two randomized placebo-controlled Phase 3 trials (Studies 047 and 048) and an open-label extension (Study 049), as well as an initial proof of concept study. The New Drug Application (NDA) included data from 163 ITP patients and was supported by a safety database of more than 4,600 subjects across other indications in which fostamatinib has been evaluated.
Tavalisse is designed to inhibit SYK, a key signaling component in the body's immune process that can lead to platelet destruction in ITP patients. Tavalisse may address an underlying autoimmune cause of ITP by impeding platelet destruction.