• Hadi Shabbir

Pfizer's COVID-19 Antiviral Compound


Pfizer is one of the few companies that have rolled out a COVID-19 vaccine to the public. Now, they are currently testing an antiviral compound as a treatment for COVID-19. They believe this potential treatment, which interrupts the virus’ ability to multiply, could be a first-in-class opportunity to help treat COVID-19 patients. As of today, there are no FDA approved antiviral treatments for COVID-19 patients. According to Pfizer, success against COVID-19 will likely require effective antiviral treatments for patients with the disease, and speed is of the essence as they work to attempt to lower the impact of COVID-19 on patients’ lives.

Certain antivirals help slow or stop a virus from replicating and thereby help reduce the symptoms associated with COVID-19 along with the risk of significant health complications. The Pfizer investigational antiviral compound is called a protease inhibitor, which interferes with part of the coronavirus needed for the virus to make copies of itself. Protease inhibitors bind to a viral enzyme called a protease, preventing the virus from replicating in the cell. Protease inhibitors have been effective at treating other viral pathogens such as HIV and hepatitis C virus, both alone and in combination with other antivirals. This compound is currently being investigated for potential treatment of COVID-19.

The protease inhibitor is called PF-07304814. This compound has been shown in pre-clinical studies to inhibit proteases used by coronaviruses to replicate, inhibiting both the coronavirus responsible for causing SARS in 2003 and the coronavirus which is causing COVID-19 today. 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. Approximately half of the participants in the study will receive the medicine through an injection in a vein and the other half will receive a placebo. Neither participants nor investigators know who is getting which. If the study is successful, they anticipate starting a Phase 2/3 trial to better understand the safety and efficacy of the compound in a larger patient population.

“Tackling the COVID-19 pandemic requires both prevention via vaccine and targeted treatment for those who contract the virus. Given the way that SARS-CoV-2 is mutating and the continued global impact of COVID-19, it appears likely that it will be critical to have access to therapeutic options both now and beyond the pandemic,” said Mikael Dolsten, MD, PhD., Chief Scientific Officer and President, Worldwide Research, Development and Medical of Pfizer. “We have designed PF-07321332 as a potential oral therapy that could be prescribed at the first sign of infection, without requiring that patients are hospitalized or in critical care. At the same time, Pfizer’s intravenous antiviral candidate is a potential novel treatment option for hospitalized patients. Together, the two have the potential to create an end to end treatment paradigm that complements vaccination in cases where disease still occurs.”

Speaking Plainly:

  • Pfizer is currently working on an antiviral compound as a treatment for COVID-19.

  • Phase 1b of the trial has already occurred.