Rigel has an exclusive license and supply agreement with Knight to commercialize TAVALISSE (fostamatinib disodium hexahydrate) in all potential indications in Latin America.
In May 2026, Knight announced that Brazil’s Agência Nacional de Vigilância Sanitária (ANVISA) approved TAVALISSE for the treatment of adult patients with chronic ITP who have had an insufficient response to a previous treatment.
In December 2024, Knight announced Mexico's Comisión Federal para la Protección contra Riesgos Sanitarios approved TAVALISSE for the treatment of thrombocytopenia in adult patients with chronic immune thrombocytopenia (ITP) who have had an insufficient response to a previous treatment.
Knight has also submitted marketing authorization applications for TAVALISSE in Colombia, Argentina and Paraguay.
Rigel received an upfront cash payment, and is eligible for additional regulatory and commercial milestone payments, and royalty payments based on tiered net sales of TAVALISSE in the territory.