The COVID-19 pandemic has likely had an impact on almost every person on Earth. As the SARS CoV-2 virus was spreading rapidly, many scientists and clinicians went in search for medications that would help fight this new virus. One source of potential medications were drugs that were already being used for other purposes and had already be shown to be safe enough to give to people for other medical reasons.
One of those medications was a drug called camostat. Camostat is an inexpensive and safe medication that is used in Japan and other countries for chronic gastrointestinal conditions. It turns out that camostat blocks one of the body’s enzymes (TMPRSS2) that the SARS-2 virus uses to enter the human cells that line our respiratory tract and cause the symptoms of COVID-19 respiratory infection and pneumonia. Camostat was also shown to work in the test tube against the SARS-2 virus. The next step in understanding whether camostat might help fight the virus in people was a randomized study that compared camostat to placebo (inactive medication) in people with mild or moderate COVID-19 who were not in the hospital. The ACTG ACTIV-2 team led this study.
More than 200 people with mild or moderate COVID-19 symptoms participated. The team was able to show that camostat was safe and had similar side effects to the placebo. However camostat did not decrease the levels of SARS-2 virus coming from the nose, did not shorten the time of symptoms, and did not have an effect on keeping people out of the hospital, all compared to placebo.
While this is a negative study, the results are important. Just because a medication works in a test tube does not mean it will work in people. During the COVID-19 pandemic, there were many reports of treatments that might work for COVID-19 and a lot of confusing information (and intentional misinformation). Comparing treatments in a randomized study is the best way to learn whether a new medication is likely to work in people. When there isn’t a good treatment available, comparing treatment to placebo in a safe carefully monitored study, like we did with camostat, helps us learn what medications to move forward and what medications to set aside.
Nikolaus Jilg et. al, One Week of Oral Camostat Versus Placebo in Nonhospitalized Adults With Mild-to-Moderate Coronavirus Disease 2019 (COVID-19): A Randomized Controlled Phase 2 Trial, Clinical Infectious Diseases, 2023;, ciad342, https://doi.org/10.1093/cid/ciad342