The Indian multinational pharmaceutical company, Sun Pharma has recently received approval from the Drugs Controller General of India (DCGI) for conducting clinical trials of a synthetic serine protease inhibitor, nafamostat mesylate against COVID-19.
The protease inhibitor drug has been used as an anticoagulant and anti-pancreatitis agent, and is approved for the treatment of cystic fibrosis as its mucolytic action can prevent lung function deterioration by lowering airways infections.
A recent study conducted by the University of Tokyo, Japan and Leibniz Institute for Primate Research, Germany revealed that nafamostat, at very low concentrations, suppressed transmembrane protease, serine 2 (TMPRSS2), a protein that the SARS-CoV-2 virus used to enter the human lung cell.
SARS-CoV-2 enters the lung cells by binding to the angiotensin-converting enzyme 2 (ACE-2) receptor and activating the TMPRSS2, which can, therefore, be targeted for potential antiviral treatment.
According to the study, nafamostat as a TMPRSS2 inhibitor prevented SARS-CoV-2 cell entry in vitro which makes it a potential drug target for COVID-19 patients.
Globally there are three ongoing clinical trials evaluating the efficacy and safety of nafamostat in COVID-19. These trials are being led by the University of Tokyo Hospital, Japan; Gyeongsang National University Hospital (South Korea); and a collaborative trial by University Hospital, Padova, Italy, University of Zurich, Switzerland and Yokohoma City University, Japan (RACONA study).