Rigel's Fostamatinib Meets Phase III Endpoint in Chronic ITP

Fostamatinib, an oral spleen tyrosine kinase inhibitor developed by Rigel Pharmaceuticals, met its primary endpoint in one of two identical Phase III studies for the treatment of adult chronic/persistent immune thrombocytopenia.

The study showed that 18 percent of 76 patients receiving fostamatinib achieved a stable platelet response, compared to none in the placebo arm.

A stable response was defined as achieving greater than 50,000 platelets per µL of blood on at least four of the last six scheduled visits between weeks 14 and 24 of treatment. Results from the second study are expected this fall.