Drug Update · Pharmacology

FDA Approves Ensitrelvir (XOCOVA) for COVID-19 Post-Exposure: 67% Lower Symptomatic Infection in SCORPIO-PEP

September 02, 2026

FDA approval date

2026-05-29

Label effective date

2026-06-03

Primary endpoint (mITT) confirmed symptomatic infection

XOCOVA 2.9% vs Placebo 9.0% (risk ratio 0.33; 95% CI 0.22-0.49)

Key secondary endpoint (ITT) confirmed symptomatic infection

XOCOVA 4.4% vs Placebo 10.2% (risk ratio 0.43; 95% CI 0.32-0.59)

Recommended dosage

375 mg Day 1; 125 mg Days 2-5 (tablets per label)

Clinical Perspective

This approval affects clinicians who manage post-exposure care for adults and adolescent patients (12 years and older) who have had contact with a person with COVID-19, providing an FDA-labeled oral PEP option ^[3]. The SCORPIO-PEP data support use of ensitrelvir to reduce confirmed symptomatic SARS-CoV-2 infection through Day 10 after exposure, based on the mITT and ITT analyses reported in the label ^[3]. How ensitrelvir will be integrated into local post-exposure strategies compared with other prevention measures and which specific patient subgroups derive the most benefit remain questions for clinicians and institutions to define based on local epidemiology and available guidance?

Dr. Pooja Sinha, MBBS, MD (General Medicine), MRCP · General Medicine

Ensitrelvir (XOCOVA) was approved by the FDA for post-exposure prophylaxis (PEP) of COVID-19 in adults and adolescents 12 years of age and older on 2026-05-29, with the label effective date 2026-06-03, based on the SCORPIO-PEP randomized trial showing a reduction in confirmed symptomatic SARS-CoV-2 infection through Day 10 versus placebo ^[3]. The SCORPIO-PEP trial met its primary and key secondary endpoints, including a 67% reduction in the mITT analysis and a 57% reduction in the ITT analysis of confirmed symptomatic COVID-19 through Day 10 ^[3].

Clinical Context

Ensitrelvir (XOCOVA) is an oral antiviral indicated for post-exposure prophylaxis of coronavirus disease 2019 (COVID-19) in adults and adolescents 12 years of age and older following contact with an individual who has COVID-19 ^[3]. The drug is described on the label as a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (M pro) inhibitor ^[3]. The approval and labeling information, including the recommended dosage and population, are provided in the FDA prescribing information and label effective 2026-06-03 ^[3]. The broader regulatory context includes the FDA’s multi-year Prescription Drug User Fee Act reauthorization (PDUFA VII) through September 2027, which supports the agency’s drug review resources and processes ^[1]. Information on other agents mentioned in the briefing topic (cytisinicline, sparsentan, roflumilast, deucravacitinib) was not reported in the provided source excerpts; Tryngolza (olezarsen) is listed among prior FDA actions with a CDER notable approval entry dated December 19, 2024 ^[2].

Key Findings

In the SCORPIO-PEP randomized, double-blind, placebo-controlled trial, XOCOVA achieved confirmed symptomatic SARS-CoV-2 infection through Day 10 in 2.9% of participants versus 9.0% with placebo in the modified intention-to-treat (mITT) population (risk ratio 0.33; 95% CI: 0.22-0.49) ^[3].
For the key secondary endpoint in the intention-to-treat (ITT) population through Day 10, XOCOVA achieved confirmed symptomatic SARS-CoV-2 infection in 4.4% versus 10.2% with placebo (risk ratio 0.43; 95% CI: 0.32-0.59) ^[3].
SCORPIO-PEP randomized a total of 2,387 subjects; the mITT analysis population comprised 2,041 subjects including 118 adolescents, with demographic and baseline characteristics reported in the label and balanced between arms ^[3].

Safety & Tolerability

Safety information was not available in the provided source excerpts.

Study Design

SCORPIO-PEP was a randomized, double-blind, placebo-controlled, multinational post-exposure prophylaxis trial conducted in 5 countries; subjects were enrolled within 72 hours of symptom onset in an index patient in the household and randomized 1:1 to ensitrelvir or placebo ^[3]. The primary endpoint was incidence of COVID-19 (onset of symptoms for at least 48 hours with RT-PCR-confirmed SARS-CoV-2 infection) within 10 days in the modified intention-to-treat (mITT) population; a key secondary endpoint used the ITT population ^[3]. A total of 2,387 subjects were randomized and the mITT population included 2,041 subjects ^[3]. Indication and approval details: XOCOVA is indicated for post-exposure prophylaxis of COVID-19 in adults and adolescents 12 years and older; FDA original approval date 2026-05-29, label effective date 2026-06-03 ^[3]. Information on trial funding or additional design elements was not available in the provided source excerpts.

FAQ

Q1 What is XOCOVA (ensitrelvir) approved for?

XOCOVA (ensitrelvir) is approved for post-exposure prophylaxis of coronavirus disease 2019 (COVID-19) in adults and adolescents 12 years of age and older following contact with an individual who has COVID-19. The approval and indication language are provided in the FDA prescribing information with an original approval date of 2026-05-29 and label effective date 2026-06-03. Clinicians should consult current prescribing information for full dosing guidance.

Q2 How does ensitrelvir work?

The prescribing information describes ensitrelvir as a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (M pro) inhibitor. The label states this mechanism in the Clinical Pharmacology and Mechanism of Action sections and identifies ensitrelvir as an antiviral targeting the viral main protease.

Q3 What is the recommended dose of XOCOVA?

The recommended dosage in adults and adolescents 12 years of age and older is 375 mg (three 125-mg tablets taken at the same time) orally on Day 1 and 125 mg (one 125-mg tablet) orally on Days 2 to 5, taken with or without food, beginning as soon as possible and within 72 hours following contact with an individual who has COVID-19. The label specifies the tablet counts and timing; Clinicians should consult current prescribing information for full dosing guidance.

Q4 What are the most common side effects of ensitrelvir?

[Information] was not available in the provided source excerpts.

Clinicians should consult current prescribing information for full dosing guidance.

FDA Approves Ensitrelvir (XOCOVA) for COVID-19 Post-Exposure: 67% Lower Symptomatic Infection in SCORPIO-PEP

Direct Clinical Takeaway & Evidence Summary

FDA Approves Ensitrelvir (XOCOVA) for COVID-19 Post-Exposure: 67% Lower Symptomatic Infection in SCORPIO-PEP

Clinical Perspective

Clinical Context

Key Findings

Safety & Tolerability

Study Design

FAQ

References

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