Rigel Pharmaceuticals (United States)

Rigel Pharmaceuticals is a biotechnology company developing small molecule drugs for immune and hematologic disorders. Based in South San Francisco, the company created Tavalisse (fostamatinib), the first oral spleen tyrosine kinase (SYK) inhibitor for chronic immune thrombocytopenia (ITP). Rigel’s research targets diseases involving aberrant immune cell signaling.