Camostat, made by a Japanese pharamaceutical company, is what's known to scientists as a serine protease inhibitor. It is not approved by the FDA for use in the U.S.
Camostat has previously been noted for its effects against the virus that caused the 2003 SARS epidemic. Research into the drug's potential against the coronavirus has been spurred by a March 2020 report of the drug's effectiveness in a laboratory test against the virus causing the 2020 pandemic. It remains to be proved whether camostat can help fight coronavirus in humans. What appears to be the first thorough clinical trial is scheduled to be finished by May 2021.