** Shares of Traws Pharma TRAW.O rise 4% to $1.57 premarket

** TRAW says it has received approval from the Human Research Ethics Committee to proceed with mid-stage study of its COVID-19 antiviral candidate, ratutrelvir

** Company expects to have results from the study by the end of this year

** In an early-stage study, patients only needed to take one tablet of ratutrelvir per day for 10 days compared to Pfizer's PFE.N Paxlovid, which requires multiple tablets twice daily for 5 days - TRAW

** Up to last close, TRAW shares down 83% YTD

(Reporting by Siddhi Mahatole)

((siddhi.mahatole@thomsonreuters.com))