 SOUTH SAN FRANCISCO, Calif., July 14, 2021 PRNewswire -- Rigel Pharmaceuticals, Inc. Nasdaq: RIGL, today announced that data from its clinical development program for TAVALISSE fostamatinib disodium hexahydrate tablets will be highlighted in two presentations at the upcoming International Society on Thrombosis and Haemostasis ISTH Virtual Congress, taking place online from July 17 21, 2021. 