Rigel Awarded $16.5 Million from U.S. Department of Defense for Phase 3 Clinical Trial of Fostamatinib in COVID-19 Patients

Rigel Pharmaceuticals, Inc. announced it has been awarded $16.5 million by the U.S. Department of Defense’s (DOD) Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense (JPEO-CBRND) to support Rigel’s ongoing Phase 3 clinical trial to evaluate the safety and efficacy of fostamatinib in hospitalized COVID-19 patients. Fostamatinib is marketed in the U.S. as TAVALISSE® (fostamatinib disodium hexahydrate) tablets, and is approved in the U.S., Europe, and Canada as a treatment for adult chronic immune thrombocytopenia (ITP).

“We are grateful to receive this funding from the DOD and for their demonstrated commitment towards finding safe and effective treatments for COVID-19 patients,” said Raul Rodriguez, Rigel’s president and CEO. “These additional resources will contribute significantly to the advancement of our Phase 3 trial. Data from this trial, coupled with findings from the NIH-sponsored Phase 2 trial, which is anticipated to report topline results in April 2021, could potentially facilitate an EUA filing for a much needed therapy for hospitalized COVID-19 patients in the U.S.”

“The DOD is pleased to support this effort, since repurposing an existing FDA-approved drug product for potential application as a COVID-19 treatment saves time and cost, enabling a much more rapid response to the pandemic,” said Dr. Jason Roos, the Joint Program Executive Officer for Chemical, Biological, Radiological and Nuclear Defense. “This investment should speed up identification of safe and effective treatments for this formidable pandemic.”

The Phase 3 clinical trial will evaluate the safety and efficacy of fostamatinib in hospitalized COVID-19 patients without respiratory failure that have certain high-risk prognostic factors. This multi-center, double-blind, placebo-controlled, adaptive design study is expected to enroll over 300 evaluable patients that will be randomly assigned to either fostamatinib plus standard of care (SOC) or matched placebo plus SOC (1:1). Treatment will be administered orally twice daily for 14 days. There will be a follow-up period to day 60. The primary endpoint of this study is the proportion of subjects who progress to severe/critical disease within 29 days.

About COVID-19 & SYK Inhibition
COVID-19 is the infectious disease caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). SARS-CoV-2 primarily infects the upper and lower respiratory tract and can lead to acute respiratory distress syndrome (ARDS). Additionally, some patients develop other organ dysfunction including myocardial injury, acute kidney injury, shock resulting in endothelial dysfunction and subsequently micro and macrovascular thrombosis.1 Much of the underlying pathology of SARS-CoV-2 is thought to be secondary to a hyperinflammatory immune response associated with increased risk of thrombosis.2

SYK is involved in the intracellular signaling pathways of many different immune cells. Therefore, SYK inhibition may improve outcomes in patients with COVID-19 via inhibition of key Fc gamma receptor (FcγR) and c-type lectin receptor (CLR) mediated drivers of pathology, such as inflammatory cytokine release by monocytes and macrophages, production of neutrophil extracellular traps (NETs) by neutrophils, and platelet aggregation.3,4,5 Furthermore, SYK inhibition in neutrophils and platelets may lead to decreased thromboinflammation, alleviating organ dysfunction in critically ill patients with COVID-19.