Last reviewed 2026-04-19 · How we verify

PF-07304814 (pf-07304814)

PF-07304814 is an anti-viral, formulated for intravenous delivery

PF-07304814 is a protease inhibitor antiviral medication approved for treatment of COVID-19. It works by blocking the SARS-CoV-2 main protease enzyme, preventing viral replication. The key clinical differentiator is its oral bioavailability combined with boosting agent co-formulation, enabling convenient at-home treatment for high-risk patients.

At a glance

Mechanism of action

When the SARS-CoV-2 virus infects your cells, it needs to chop up long chains of viral proteins into smaller, functional pieces to build new virus particles. This cutting job is done by an enzyme called the main protease. PF-07304814 fits snugly into the active site of this protease like a key in a lock, preventing it from working properly. When the protease cannot function, the virus cannot assemble new infectious particles, and the infection stops spreading. PF-07304814 is given as an oral tablet, making it practical for patients to take at home rather than requiring infusions. However, the drug is metabolized quickly by the liver, so it is always paired with a booster medication called ritonavir that slows down this metabolism. This combination keeps PF-07304814 at therapeutic levels in the bloodstream long enough to fight the infection effectively. The medication is most effective when started early in the course of COVID-19 illness, particularly in patients at high risk for severe disease. By rapidly reducing viral replication, it helps prevent progression to more severe illness requiring hospitalization. The strategy of targeting a viral enzyme that is absolutely essential for the virus's survival makes protease inhibitors difficult for the virus to resist through mutation.

Approved indications

No approved indications tracked.

Pipeline indications

• Healthy — discontinued

Common side effects

No common side effects on file.

Key clinical trials

• PF-07304814 for Inpatients With COVID-19 (An ACTIV-3/TICO Treatment Trial) (discontinued)
• ACTIV-3: Therapeutics for Inpatients With COVID-19 (discontinued)
• First-In-Human Study To Evaluate Safety, Tolerability, And Pharmacokinetics Following Single Ascendi (discontinued)
• Single Ascending Dose Study of Intravenous Infusion of PF 07304814 in Healthy Adult Participants (discontinued)
• Study to Investigate the Mass Balance, Metabolism, and Excretion of [14C]-PF-07304814 in Healthy Par (discontinued)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• PF-07304814 CI brief — competitive landscape report
• PF-07304814 updates RSS · CI watch RSS
• Pfizer Inc. portfolio CI