The U.S. Food and Drug Administration (FDA) has approved Xocova (ensitrelvir), developed by Japanese pharmaceutical company Shionogi & Co., for the prevention of COVID-19 following exposure to an infected individual. The approval makes Xocova the first and only oral antiviral therapy authorized in the United States for post-exposure prophylaxis of COVID-19.
The newly approved indication covers adults and adolescents aged 12 years and older who have been exposed to someone with COVID-19. Until now, no oral medication had demonstrated sufficient evidence to gain FDA approval for preventing symptomatic COVID-19 after exposure, leaving a significant gap in prevention strategies, particularly for individuals at higher risk of severe disease.
FDA's decision was based on results from the Phase 3 SCORPIO-PEP study, which evaluated ensitrelvir as a post-exposure preventive treatment. According to Shionogi, the trial met its primary endpoint by significantly reducing the development of symptomatic COVID-19 among people who had recently been exposed to the virus. The study is considered the first successful Phase 3 trial of an oral antiviral for COVID-19 post-exposure prevention.
The pivotal SCORPIO-PEP trial enrolled more than 2,000 participants who had been exposed to COVID-19 through infected household contacts. Symptomatic COVID-19 developed in 2.9% of participants receiving ensitrelvir compared with 9.0% in the placebo group. Additionally, 14% of patients receiving the antiviral tested positive for SARS-CoV-2 versus 21.5% in the placebo arm, highlighting the drug's potential to reduce both infection and disease development after exposure.
Ensitrelvir works by blocking the SARS-CoV-2 main protease, an enzyme essential for viral replication. The drug was previously approved in Japan and Singapore for COVID-19 treatment and prevention-related indications. With the latest FDA approval, Shionogi expands its presence in the global COVID-19 therapeutics market and introduces a new option for reducing infection risk after exposure.
Company officials described the approval as an important milestone in antiviral drug development. They noted that Xocova demonstrated preventive benefits regardless of vaccination status or previous COVID-19 infection history among study participants.
The approval comes as healthcare systems continue to seek effective tools to protect vulnerable populations from COVID-19 outbreaks. Experts believe an oral post-exposure treatment could be particularly useful in households, healthcare settings, and other environments where close contact with infected individuals increases transmission risk.
