Antiviral

• Merck & Co. is considering the use of molnupiravir, an antiviral drug previously authorized for COVID-19 treatment, to combat a worsening Ebola outbreak in central Africa. • The move comes as governments and health authorities struggle to respond to the escalating public health crisis in the region. • Repurposing an existing antiviral could provide a faster therapeutic option for patients as the outbreak intensifies.

• The U.S. FDA has approved ensitrelvir (Xocova), an oral antiviral developed by Shionogi, for the post-exposure prevention of COVID-19. • The medication is authorized for use in individuals aged 12 years and older who have been exposed to the SARS-CoV-2 virus. • This approval is significant as Xocova becomes the first and only oral medication specifically authorized to reduce the risk of infection after a known exposure.

• The FDA has approved ensitrelvir, an oral antiviral medication specifically designed to prevent COVID-19 after a person has been exposed to the virus. • Approval follows the phase III SCORPIO-PEP trial, which demonstrated that the drug reduced the risk of developing COVID-19 by more than half for individuals who were household contacts of an infected person. • This marks a significant shift in prevention strategy, though the medication is currently not approved for treating active COVID-19 infections within the U.S.

• Shionogi has received FDA approval for its protease inhibitor, ensitrelvir, specifically for use in the prevention of COVID-19. • This regulatory win follows a previous failure by the company to demonstrate the drug's effectiveness as a primary treatment for U.S. patients. • The approval is significant as it expands the available preventative options against the virus, leveraging a drug already approved in Japan.

• Researchers tested ARN-75039, an orally bioavailable small-molecule inhibitor, as a potential therapeutic against Lassa virus, which causes Lassa fever—a disease for which no preventative vaccine currently exists. • The compound represents a new approach to treating Lassa virus infection through direct viral entry inhibition rather than vaccines. • This research advances therapeutic options for a high-consequence pathogen that poses public health concerns, particularly in West African endemic regions.