In a recent paper on why hydroxychloroquine doesn't really work against Covid-19, it's been demonstrated that SARS-CoV-2 is much better at taking advantage of TMPRSS2 at the cell membrane surface, so that the cathepsin-mediated endosomal-entry pathway (which hydroxychloroquine inhibits) is basically irrelevant most of the time for SARS-CoV-2 infections in the cells it actually infects in humans.

There is one inhibitor of TMPRSS2 mentioned in that paper namely camostat, but it seems it's only approved as a drug in Japan and for other diseases: pancreatitis etc. Wikipedia does cite one small-scale retrospective study of camostat for Covid-19 (but actually conducted in Germany). That paper ends with the predictable suggestion that "Camostat mesylate thus warrants further evaluation within randomized clinical trials."

I also found an older (2017) review on other TMPRSS2 inhibitors, but it's not exactly clear if any of the [other] compounds mentioned (aprotinin, nafamostat, AEBSF, leupeptin, bromhexine hydrochloride, and a few more which only have [long] chemical names) has been tested in any way against Covid-19, although some of these compounds were previously tested against influenzas. So, has any RCTs for a TMPRSS2 inhibitor been even started for Covid-19? Or is there some (other) reason to think such drugs would likely not be useful against Covid-19, so it makes no sense to test them?

1 Answer 1


Yes, there are a number of trials.

16 of these studies are recruiting, 1 study started in April 2020, is no longer recruiting and will finish in May 2021 and no trials have been completed so far.

  • 1
    Based on those it seems camostat and nafamostat (roughly in that order) are the ones most investigated in western countries, with a multi-site trial in the US (and also a similar one in France and one in Germany) for camostat . Feb 12, 2021 at 15:55
  • @Fizz Please go ahead and post a more elaborate answer using my links - I don't have enough time at my hands to do it more rigorously. (Maybe this answer should have been a comment, tbh)
    – Narusan
    Feb 12, 2021 at 15:56
  • 1
    If someone posts a more elaborate answer using your data, flag this answer for me and I'll convert it to a comment.
    – Carey Gregory
    Feb 12, 2021 at 19:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.