Actor portrayal.

Why PEP (post‑exposure prophylaxis)

Sick father in the living room

Actor portrayal.

COVID-19 remains highly transmissible and continues to put patients and loved ones at risk1-3

Household infections are fueling viral transmission in the wider community

  • 43%–47% of household contacts experienced a SARS-CoV-2 infection during the Omicron wave1,2
  • COVID-19 is up to 3x more likely to spread in close-contact settings, such as households and long-term care facilities3

Low vaccination rates and vaccine efficacy limitations in certain patients may contribute to continued COVID-19 spread.4,5

Most adults in the US are still at high risk for severe consequences of COVID-19 due to factors such as6-8:

  • ≥65 years of age
  • Obesity
  • Diabetes
  • Heart condition
  • Chronic kidney disease
  • Chronic lung disease
  • Cancer
  • Immunocompromised condition

Current COVID-19 prevention strategies may still leave patients vulnerable5,9,10

Discover how XOCOVA works

INDICATION & IMPORTANT SAFETY INFORMATION

INDICATION

XOCOVA (ensitrelvir) is indicated for post-exposure prophylaxis (PEP) 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.

IMPORTANT SAFETY INFORMATION

Contraindications

XOCOVA is contraindicated in patients with a history of clinically significant hypersensitivity reactions to XOCOVA or any of its components. XOCOVA is also contraindicated when administered with drugs primarily metabolized by CYP3A for which elevated concentrations may be associated with serious and/or life-threatening reactions or when administered with strong CYP3A inducers because they may significantly reduce XOCOVA plasma concentrations leading to potential loss of virologic response.

Embryofetal Toxicity

Based on animal data, XOCOVA may cause fetal harm when administered to a pregnant woman. Advise pregnant women and females of reproductive potential that XOCOVA may cause fetal harm. Verify pregnancy status of females of reproductive potential before initiating XOCOVA and advise using effective contraception during XOCOVA use and for 2 weeks after the final dose.

Risk of Serious Adverse Reactions Due to Drug Interactions

XOCOVA is a strong CYP3A inhibitor and an inhibitor of P-gp and BCRP. In patients receiving or initiating medications metabolized by CYP3A or transported by P-gp or BCRP, XOCOVA may increase plasma concentrations of those medications and may potentially lead to severe, life-threatening, or fatal events from increased exposure. CYP3A inducers may decrease concentrations of XOCOVA, leading to loss of therapeutic effect.

Before prescribing XOCOVA, review all concomitant medications to assess potential drug-drug interactions and determine if those medications require a dose adjustment, interruption, and/or additional monitoring. Consider the benefit of XOCOVA and whether risk of potential drug-drug interactions can be managed.

Hypersensitivity Reactions Including Anaphylaxis

Hypersensitivity reactions, including anaphylaxis, anaphylactic shock, and angioedema have been reported. If signs and symptoms of a clinically significant hypersensitivity reaction occur, immediately discontinue XOCOVA and initiate appropriate treatment.

Lactation

There are no data on the presence of XOCOVA in human milk, effects on breastfed infants, or effects on milk production. XOCOVA was present in the milk of lactating rats. Advise women not to breastfeed while on XOCOVA and for 2 weeks after the final dose.

Adverse Reactions

The most common adverse events occurring in ≥1% of XOCOVA patients and at greater frequency than placebo, respectively, were headache (2.9% vs 2.6%), diarrhea (1.7% vs 1.3%), and cough (1.1% vs 0.6%).

Laboratory Abnormalities

Asymptomatic hemoglobin declines from baseline of >2 g/dL occurred in XOCOVA and placebo patients (3% vs 1%, respectively).

References: 1. Madewell ZJ, Yang Y, Longini IM Jr, Halloran ME, Dean NE. Household secondary attack rates of SARS-CoV-2 by variant and vaccination status: an updated systematic review and meta-analysis. JAMA Netw Open. 2022;5(4):e229317. 2. Baker JM, Nakayama JY, O'Hegarty M, et al. Household transmission of SARS-CoV-2 in five US jurisdictions: comparison of Delta and Omicron variants. PLoS One. 2025;20(1):e0313680. 3. Sumsuzzman DM, Ye Y, Wang Z, et al. Impact of disease severity, age, sex, comorbidity, and vaccination on secondary attack rates of SARS-CoV-2: a global systematic review and meta-analysis. BMC Infect Dis. 2025;25(1):215. 4. U.S. Centers for Disease Control and Prevention. Vaccination trends. Updated March 13, 2026. Accessed March 18, 2026. https://www.cdc.gov/respiratory-viruses/data/vaccination-trends.html 5. Link-Gelles R, Chickery S, Webber A, et al. Interim estimates of 2024–2025 COVID-19 vaccine effectiveness among adults aged ≥18 years — VISION and IVY networks, September 2024–January 2025. MMWR Morb Mortal Wkly Rep. 2025;74(6):73-82. 6. Ajufo E, Rao S, Navar AM, Pandey A, Ayers CR, Khera A. U.S. population at increased risk of severe illness from COVID-19. Am J Prev Cardiol. 2021;6:100156. 7. U.S. Centers for Disease Control and Prevention. People with certain medical conditions and COVID-19 risk factors. Updated June 11, 2025. Accessed March 18, 2026. https://www.cdc.gov/covid/risk-factors/index.html 8. Watson KB, Wiltz JL, Nhim K, Kaufmann RB, Thomas CW, Greenlund KJ. Trends in multiple chronic conditions among US adults, by life stage, behavioral risk factor surveillance system, 2013–2023. Prev Chronic Dis. 2025;22:E15. 9. U.S. Centers for Disease Control and Prevention. Updated February 5, 2026. Accessed April 21, 2026. https://www.cdc.gov/covid/treatment/index.html 10. U.S. Centers for Disease Control and Prevention. Staying up to date with COVID-19 vaccines. Updated November 19, 2025. Accessed March 18, 2026. https://www.cdc.gov/covid/vaccines/stay-up-to-date.html