Pfizer kicks off trial for COVID-19 oral antiviral candidate

27-Sep-2021 - Last updated on 27-Sep-2021 at 15:57 GMT

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Related tags Pfizer Antivirals Phase II Phase 3 COVID-19 Coronavirus

The protease inhibitor PF-07321332 (co-administered with ritonavir) is designed for patients exposed to (or showing the first signs of) the COVID-19 virus.

Pfizer has announced the commencement of Evaluation of Protease Inhibition for COVID-19 in Post-Exposure Prophylaxis (EPIC-PEP), a Phase II/III study examining the use of a novel antiviral candidate for post-exposure prophylaxis in adult patients. This study will evaluate the ability of protease inhibitor PF-07321332 (to be administered along with a low dose of ritonavir, another protease inhibitor) to prevent illness in adults dwelling in the same household as someone else diagnosed with COVID-19.

According to Pfizer, the Phase II/III trial is enrolling patients 18 years of age or older who are living with other individuals diagnosed with SARS-CoV-2 and showing symptoms. Mikael Dolsten (chief scientific officer and president of worldwide research, development, and medical for Pfizer), said coming up with ways to successfully treat the virus will be key in stemming the COVID-19 pandemic.

“With the continued impact of COVID-19 around the world, we believe that tackling the virus will require effective treatments for people who contract, or have been exposed to, the virus, complementing the impact that vaccines have had in helping quell infections,” Dolsten said. “If successful, we believe this therapy could help stop the virus early – before it has had a chance to replicate extensively – potentially preventing symptomatic disease in those who have been exposed and inhibiting the onset of infection in others.”

Dolsten added, “Given the continued emergence and evolution of SARS-CoV-2 variants and their immense impact, we continue to work diligently to develop and study new ways that our investigational oral antiviral candidate could potentially lower the impact of COVID-19, not only on patients’ lives but also the lives of their families and household members.”

The EPIC-PEP trial is a randomized, double-blind, placebo-controlled study; researchers intend to enroll up to 2,660 healthy adult participants aged 18 and older. Participants will be randomly assigned (1:1:1) to receive PF-07321332/ritonavir or placebo orally twice daily for 5 or 10 days.

According to the research team, the primary objective is to assess the treatment’s safety and efficacy for the prevention of confirmed SARS-CoV-2 infection and its symptoms through Day 14. PF-07321332 is an oral antiviral SARS-CoV-2-3CL protease inhibitor, which reportedly has an encouraging pre-clinical profile, including potent in vitro antiviral SARS-CoV-2 and broad coronavirus activity. Researchers related that results from the Phase I clinical trial demonstrated PF-07321332 was safe and well-tolerated.

In addition to the EPIC-PEP trial, Pfizer’s global EPIC program consists of multiple ongoing clinical trials, including one in SARS-CoV-2 infected patients at high risk of developing severe illness (including hospitalization or death); that study started in July 2021. Another study, launched in August 2021, involved infected patients at standard risk (that is, with no risk factors for severe illness).