Repurposing hopes for Tavalisse in COVID-19 breathe life into Rigel shares

Rigel is the latest beneficiary of investor exuberance for COVID-19 plays.

Shares of Rigel Pharmaceuticals Inc. (NASDAQ:RIGL) gained 91% to $4.12, giving the company a market cap of nearly $700 million, after it said on Tuesday Imperial College London will evaluate the efficacy of Tavalisse fostamatinib to treat COVID-19 pneumonia. The oral inhibitor of SYK -- a mediator of immunoreceptor signaling in inflammatory cells -- is approved in the U.S. and Europe for adult chronic immune thrombocytopenia (ITP). ...