U.S. regulators have approved the first oral medication intended to help prevent COVID-19 in people who have been exposed to the virus but are not yet infected, marking a shift in how the disease may be managed beyond vaccines and after-the-fact treatments.
The Food and Drug Administration approved Xocova, known generically as ensitrelvir, on June 1. The drug is made by the Japanese pharmaceutical company Shionogi. It is cleared for post-exposure prophylaxis in adults and adolescents aged 12 and older who have come into contact with someone infected with the virus that causes COVID-19.
Until now, the prevention toolkit centered on vaccination, while antiviral pills such as nirmatrelvir were reserved for people who had already tested positive. Xocova is the first oral option designed to be taken after a known exposure to reduce the chance of developing symptomatic illness, filling a gap that has persisted since the early years of the pandemic.
The treatment is taken over five days. According to the approved regimen, patients take three tablets on the first day, followed by a single tablet on each of the next four days. The simplicity of an at-home oral course is seen as a practical advantage over injectable or clinic-administered alternatives.
The approval rested on results from SCORPIO-PEP, a global Phase 3 randomized, double-blind, placebo-controlled trial that tested the drug in household contacts of infected individuals. The study found that ensitrelvir reduced the relative risk of symptomatic COVID-19 by roughly two-thirds compared with placebo. Among uninfected household members who received the drug within days of a household member’s symptom onset, infection rates were lower than in those given placebo. The benefit held across participants regardless of their vaccination history or prior infection. The trial findings were published in a leading medical journal in May.
The FDA acted ahead of its scheduled decision deadline of June 16, signaling a relatively swift path through review. The agency’s clearance applies specifically to prevention after exposure and does not change existing guidance on vaccination, which remains the primary public health tool against severe disease.
Public health experts have long noted that exposed individuals, particularly those sharing a home with an infected person, face elevated odds of catching the virus in the days that follow. An oral preventive option could be relevant for households, congregate settings and people at higher risk of complications, although prescribing decisions will rest with clinicians.
As with any antiviral, questions remain about real-world uptake, cost and how the drug will be positioned alongside vaccines and existing treatments. Shionogi has marketed ensitrelvir in other countries, and the U.S. approval expands its footprint in a market where demand for COVID-19 products has fluctuated. Patients are advised to consult a healthcare provider about whether the medication is appropriate for their situation.
