How XOCOVA works

Mechanism of action

Introducing XOCOVA, a SARS-CoV-2 main protease (Mpro) inhibitor that blocks viral replication across many common strains1*

SARS-CoV-2 with Mpro

BINDS

to SARS-CoV-2 main protease (Mpro), an essential enzyme1-3

Virus being inhibited

INHIBITS

Mpro from processing viral polyproteins1,3

Virus being blocked

BLOCKS

SARS-CoV-2 from replicating1,2

Simplified illustrative representation.
XOCOVA inhibited the activity of recombinant SARS-CoV-2 Mpro in a biochemical assay.1

Achieves effective antiviral concentration after the first dose1†

*Mpro is believed to be less prone to mutation than the spike protein; therefore, targeting Mpro helps support the effect of XOCOVA across different variants. XOCOVA exhibited antiviral activity against infection of the SARS-CoV-2 Delta and Omicron BA.1, BE.1, and XBB.1.5 variants in primary human nasal or bronchial epithelial cells.1,4

Maximum concentration was reached at a median of 2.5 hours (range, 1.5-8.0 hours) after the drug was taken.1

Learn about dosing for XOCOVA

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. XOCOVA [package insert]. Florham Park, NJ: Shionogi Inc. 2. V'kovski P, Kratzel A, Steiner S, Stalder H, Thiel V. Coronavirus biology and replication: implications for SARS-CoV-2. Nat Rev Micobiol. 2021;19(3):155-170. 3. Patel CN, Jani SP, Jaiswal DG, et al. Identification of antiviral phytochemicals as a potential SARS-CoV-2 main protease (Mpro) inhibitor using docking and molecular dynamics simulations. Sci Rep. 2021;11(1):20295. 4. Kawashima A, Matsui T, Adachi T, et al. Ensitrelvir is effective against SARS-CoV-2 3CL protease mutants circulating globally. Biochem Biophys Res Commun. 2023;645:132-136.