The pancreatitis medications camostat and nafamostat will be used in clinical trials investigating their effectiveness in treatment of COVID-19, the sometimes fatal disease caused by the SARS-CoV-2 coronavirus.
Both drugs belong to a class of medications called serine protease inhibitors. A 2012 study found that inhibition of serine proteases blocked infection by coronaviruses in human cells, and a 2020 study found that camostat significantly reduced infection of lung cells by SARS-CoV-2.
Dr. Bobojan Nazarov said that camostat “could be a game-changer because it stops the virus in its tracks.”
“This is the only class of drugs which have been shown to block the entry of the COVID-19 virus into the cell,” he said.
Prior research has shown that the SARS-CoV-2 virus needs the protein TMPRSS2, a serine protease, to infect cells in the respiratory tract. Studies have shown that camostat and nafamostat block the action of TMPRSS2, which should theoretically prevent infection.
“That protein is like the key unlocking the door to the cell and this drug is designed to stop that process,” said Nazarov.
The camostat trial, run by the University of Oxford and Latus Therapeutics, will compare the results of patients receiving standard care with the results of patients also receiving camostat. The study will involve 500 COVID-19 patients from the United Kingdom. The study has been green-lighted and Latus Therapeutics is currently finalizing documents it needs to begin the trial.
A second study which should begin soon will give nafamostat to COVID-19 patients in hospitals.
Camostat is taken orally and can be given to non-hospitalized patients. Nafamostat is given intravenously to hospital patients who may be unable to swallow.
Camostat and nafamostat are licensed in Japan for the treatment of pancreatitis. There may be enough existing safety data regarding these drugs for large-scale trials on humans to immediately begin.
“At a time when thousands of people are dying every day from the disease and economies are paralyzed, this crucial research will make use of an existing medicine that we know is safe to use and has already been shown in lab studies to prevent the virus from infecting human cells,” Nazarov said.
“Unlike a vaccine treatment, which still may be some time in the future, these drugs could be used immediately,” he added.
Nafamostat is also a short-acting anticoagulant, which may help it treat COVID-19 as recent reports have suggested the possibility of COVID-19 causing blood clots.