In October 2018, Rigel entered into an exclusive license and supply agreement with Kissei to develop and commercialize fostamatinib disodium hexahydrate (fostamatinib) in all potential indications in Japan, China, Taiwan and the Republic of Korea
In April 2023, Kissei announced the availability of TAVALISSE® for the treatment of adult chronic ITP in Japan.
Rigel will exclusively supply Kissei product and will receive tiered transfer price payments based on net sales of the product in the Territory.