FDA Approves Ensitrelvir to Prevent COVID-19 After Exposure - Summary - MDSpire

FDA Approves Ensitrelvir to Prevent COVID-19 After Exposure

Phase 3 data showed a 67% reduction in symptomatic infection among exposed household contacts who tested negative at baseline.

  • By

  • Kathryn Wighton

  • June 2, 2026

  • 3 min

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Objective:

To report the FDA approval of ensitrelvir for postexposure prophylaxis of COVID-19.

Key Findings:
  • Ensitrelvir reduced the risk of symptomatic COVID-19 by 67% through day 10 compared with placebo.
  • Overall adverse event rates were similar between treatment groups, with 15.1% in the ensitrelvir group and 15.5% in the placebo group.
  • The most common adverse events were headache, diarrhea, and cough.
Interpretation:

Limitations:
  • Participants had evidence of prior SARS-CoV-2 infection, vaccination, or both, which may limit generalizability based on study findings.
Conclusion:

Original Source(s)

FDA Approves Ensitrelvir to Prevent COVID-19 After Exposure

  • by Kathryn Wighton

  • June 2, 2026

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