Camostat mesylate flops against SARS-CoV-2

The serine protease inhibitor camostat mesylate does not appear to be an effective antiviral agent in patients with early-phase COVID-19, having failed to stop SARS-CoV-2 in its tracks in a phase II trial.

The trial included 90 participants (median age 40 years, 54.4 percent female): symptomatic (maximum 5 days) and asymptomatic patients with confirmed COVID-19 infection. They were randomized to receive either camostat mesylate (n=61) or placebo (n=21).

Researchers assessed treatment efficacy based on a change in nasopharyngeal viral load, time to clinical improvement, the presence of neutralizing antibodies, and safety.

At baseline, 77 (85.6 percent) patients presented with symptoms, including coughing (n=68, 79.1 percent), asthenia (n=64, 74.4 percent), sneezing (n=62, 72.1 percent), stuffy nose (n=56, 65.1 percent), and abnormal sense of smell or taste (n=17, 19.8 percent). Three patients received their first COVID-19 vaccination dose prior to enrolment, while another three did during the study period. One patient received two doses prior to enrolment.

There was no significant difference in the estimated change in cycle threshold at day 5 between the camostat and placebo groups (mean, 1.183; p=0.511). Likewise, clinical improvement did not differ between the two groups, with an unadjusted hazard ratio of 0.965 (95 percent confidence interval, 0.480–1.942; p=0.921).

Finally, the percentage distribution of the 50 percent neutralizing antibody titre at day 28 and frequency of adverse events were similar in the two groups.