A pill can stop people from developing COVID after being exposed to the virus, trial finds

Key Points:

• Ensitrelvir, an antiviral pill developed by Shionogi, has been shown in a late-stage trial to significantly reduce the risk of developing COVID-19 symptoms after exposure, marking the first effective post-exposure preventative treatment for the virus.
• The double-blind trial involved over 2,000 participants exposed to SARS-CoV-2 through household contacts, with only 2.9% of those taking ensitrelvir developing symptoms compared to 9% in the placebo group.
• Ensitrelvir works by inhibiting a key viral enzyme and demonstrated a favorable safety profile, with side effects comparable to placebo and only temporary changes in cholesterol and blood fat levels.
• The drug, approved in Japan and Singapore for both treatment and prevention, could potentially protect individuals in other high-risk settings such as nursing homes, though further studies are needed for those populations.
• Regulatory authorities in the U.S. and Europe are currently reviewing the trial data as they consider approving ensitrelvir for COVID-19 prevention following exposure.