Efficacy and safety of camostat mesylate in early COVID-19 disease in an ambulatory setting: a randomized placebo-controlled phase II trial

•Treatment with camostat did not affect the cycle threshold change in the early phase of COVID-19 disease.•Clinical improvement was similar in patients with COVID-19 treated with camostat or a placebo.•Treatment with camostat did not affect the SARS-CoV-2 neutralizing antibody response.•This randomized controlled trial showed the safe use of 300 mg camostat three times daily in patients with COVID-19.•Camostat mesylate is not effective as an antiviral drug for ambulatory patients with COVID-19.