Tavalisse Approved for Treatment of Chronic Immune Thrombocytopenia

Drug indicated for adults unresponsive to previous therapies

The FDA has approved fostamatinib disodium hexahydrate (Tavalisse, Rigel Pharmaceuticals, Inc.) for the treatment of thrombocytopenia in adult patients with chronic immune thrombocytopenia (ITP) who have had an insufficient response to a previous treatment. Fostamatinib 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 fostamatinib in the United States in late May 2018.

The FDA approval of fostamatinib 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 included data from 163 ITP patients and was supported by a safety database of more than 4,600 patients across other indications in which fostamatinib has been evaluated.

In patients with ITP, the immune system attacks and destroys the body's own blood platelets, which play an active role in blood clotting and healing. Common symptoms of ITP include excessive bruising, bleeding, and fatigue. People suffering with chronic ITP may live with an increased risk of severe bleeding events that can result in serious medical complications or even death. Current therapies for ITP include steroids, blood platelet production boosters, and splenectomy. However, not all patients have an adequate treatment response with existing therapies. As a result, there remains a significant medical need for additional treatment options for patients with ITP.

Source: Rigel Pharmaceuticals; April 17, 2018.