Rigel Pharmaceuticals is a biotechnology company based in California that focuses on discovering and developing small molecule drugs to treat hematologic disorders, cancer, and rare immune diseases. They have developed Tavalisse, an oral spleen tyrosine kinase inhibitor, and are currently developing Fostamatinib and R289 for a range of clinical trials. Additionally, Rigel has entered into research and license agreements with various pharmaceutical companies for the development of different drugs.