How do antivirals contribute to the treatment of COVID-19?

Certain antivirals help slow or stop a virus from replicating and thereby help reduce the symptoms associated with COVID-19 and the risk of significant health complications. The Pfizer investigational antiviral compound is a type of compound called a protease inhibitor, which interferes with part of the coronavirus needed for the virus to make copies of itself. This compound is currently being investigated for potential treatment of COVID-19.

What is the clinical status of PF-07304814?

Pfizer initiated a Phase 1b trial for PF-07304814 in September. The study will evaluate the safety, tolerability and pharmacokinetics of PF-07304814 in patients with SARS-CoV-2 virus infection and with mild-to-moderate symptoms, PF-07304814 is a phosphate prodrug that when administered intravenously is metabolized to the active compound PF-00835321, which is shown to be a very potent inhibitor of the SARS-CoV-2 coronavirus (or COVID-19) in pre-clinical studies. The study is double-blind and placebo-controlled, meaning approximately half of the participants will receive the study medicine intravenously and the other half will receive a placebo (an injection with no active ingredient) and neither participants nor investigators know who is getting which. If the study is successful, we anticipate starting a Phase 2/3 trial to better understand the safety and efficacy of the compound in a larger patient population.

When do you expect to announce results from the Phase 1b study?

We initiated the Phase 1b study in September and recently began dosing. We expect this trial to readout as early as late 2020 and, subject to the outcome of the on-going trial, we are planning a pivotal Phase 2/3 trial to begin in 2021, with a projected approval in the second half of 2021.

Is Pfizer investigating other antiviral candidates for COVID-19?

At this time, Pfizer is evaluating only its protease compound PF-07304814 in a Phase 1b study.

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COVID-19 Treatment Efforts

Advancing A Novel SARS-CoV-2 Treatment

The COVID-19 pandemic has taken a significant toll on patients, families, and communities around the globe. At Pfizer, we believe multiple public health tools – including vaccines and treatments – will be critical to efforts to combat the virus and protect lives. In early 2020, recognizing the urgency of the situation, we initiated a drug design and development program – which originated and advanced in our labs – to develop a potentially safe and effective oral treatment that could complement vaccination efforts and help prevent severe illness. We assembled a committed, multidisciplinary team with the goal of delivering a novel therapeutic compound that could be administered orally, maintain potent activity against SARS-CoV-2, and have the potential to be effective against other coronaviruses.

Using state-of-the-art computational and structure-based design capabilities, combined with our legacy in developing oral therapeutics, Pfizer researchers identified a promising pre-clinical candidate – which is a main protease, or Mpro, inhibitor – which we progressed into the clinic and, ultimately, to regulatory submission for Emergency Use Authorization.

Developing potential COVID-19 treatments is only possible through the dedicated work of our scientific collaborators, clinical research partners, and individuals who volunteer to take part in clinical trials. We are grateful to all those who are partnering with us in this effort and to all the participants who have volunteered, and will volunteer, to help attempt to achieve our shared goal of making a difference for society.

When do you expect to announce results from your clinical studies?
Results from the first of the Phase 2/3 clinical studies – in non-hospitalized patients with confirmed COVID-19 who are at high risk of progression to severe illness (i.e. hospitalization or death) – were shared from the interim and final analyses, and more information is available here. The data have been submitted to a peer-reviewed journal for publication.
Interim results from the EPIC-SR (Evaluation of Protease Inhibition for COVID-19 in Standard-Risk Patients) study were also shared, and more information is available here. Additional EPIC-SR results, as well as results from the EPIC-PEP (Evaluation of Protease Inhibition for COVID-19 in Post-Exposure Propylaxis) study, will be shared once the trials and analyses of the data are complete.
Where can I learn more about current research findings?
Pfizer is committed to transparency on its research findings related to COVID-19, as set forth in the company’s five-point plan for the biopharmaceutical industry to tackle disease caused by the novel coronavirus.
Science has published a paper on the design and preclinical profile of PF-07321332, including its in vitro pan-coronavirus antiviral activity, in vivo efficacy, and selectivity and preclinical safety profile. Results were also shared from the interim and final analyses of the Phase 2/3 EPIC-HR study, and more information is available here. Results from multiple in vitro studies demonstrating the treatment’s efficacy against Variants of Concern (VoC) are available here.

Learn more about our approach and efforts to bring treatments to patients:

Equitable Global Access to COVID-19 Treatments

Learn more about Pfizer’s commitment to equitable access of our COVID-19 oral treatment.

Pfizer’s oral treatment for COVID-19 has not been approved, but has been authorized for emergency use by FDA under an EUA, for the treatment of mild-to-moderate COVID-19 in adults and pediatric patients (12 years of age and older weighing at least 40 kg) with positive results of direct SARS CoV-2 viral testing, and who are at high-risk for progression to severe COVID-19, including hospitalization or death.

The emergency use of Pfizer’s oral treatment for COVID-19 is only authorized for the duration of the declaration that circumstances exist justifying the authorization of the emergency use of drugs and biological products during the COVID-19 pandemic under Section 564(b)(1) of the Act, 21 U.S.C. § 360bbb-3(b)(1), unless the declaration is terminated or authorization revoked sooner. See EUA Fact Sheet: www.COVID19oralRx.com.

For additional information about Pfizer, please see our filings with the U.S. Securities and Exchange Commission, including the information provided in the sections captioned “Risk Factors” and “Forward-Looking Information and Factors that May Affect Future Results”.