Daiichi Sankyo in March started a clinical trial in Japan of an inhaled form of nafamostat mesylate with COVID-19 patients. The company said in a statement it was discontinuing the trial without citing a reason. The Nikkei newspaper reported that there were safety concerns.

Nafamostat is used in the treatment of pancreatitis and has antiviral properties.

(Reporting by Rocky Swift, editing by Louise Heavens)