On Jun. 29, 2021, Rigel Pharma announced that fostamatinib, the Company’s novel oral spleen tyrosine kinase (SYK) inhibitor, had been selected for a National Institutes of Health (NIH) ACTIV-4 (Accelerating COVID-19 Therapeutic Interventions and Vaccines) trial in hospitalized patients with COVID-19.

The ACTIV-4 Host Tissue trial was funded by the National Heart, Lung, and Blood Institute and coordinated by Vanderbilt University Medical Center. The trial evaluated treatments, including fostamatinib, that aim to protect and heal host tissues in hospitalized patients with COVID-19.