European regulators have validated Rigel Pharmaceuticals’ application to market fostamatinib for adult chronic immune thrombocytopenia (ITP).

Chronic ITP is a rare, autoimmune disease in which the immune system destroys platelets, which are necessary for normal blood clotting. The disorder is difficult to treat because it is impossible to predict how people will respond to available therapies.

Fostamatinib, a SYK inhibitor, has a unique mechanism of action in that it targets the underlying autoimmune cause of the disease by impeding platelet destruction.

"The EMA's validation of our MAA is an important milestone in the execution of our global commercial strategy for fostamatinib for the treatment of adult chronic ITP," said Raul Rodriguez, president and chief executive of Rigel.

"Europe is the second largest ITP market, and we are working diligently to secure a European commercial collaboration in 2019.”

Currently, fostamatinib is commercially available in the US under the brand name Tavalisse (fostamatinib disodium hexahydrate).

The company anticipates a decision from the Committee on Human Medicinal Products by the fourth quarter of 2019.

Rigel licensed fostamatinib to AstraZeneca in 2010 for development in rheumatoid arthritis, but the drug giant returned rights in 2013 after a lack-luster performance in Phase III trials.