The company that has provided enough vaccines to inoculate more than five million Israelis against COVID-19 announced Tuesday that it is initiating a Phase I trial of a new oral treatment for the virus.
Pfizer said it is beginning a randomized, double-blind, sponsor-open, placebo-controlled, single- and multiple-dose study of its PF-07321332 treatment in healthy adults to evaluate the safety and tolerability of the drug, and generally how the body responds to it.
The trial comes after completion of preclinical trials of the treatment – described by the company as a “potent protease inhibitor” – that showed antiviral activity specifically against SARS-CoV-2, as well as other coronaviruses.
This is the first orally administered coronavirus-specific investigational protease inhibitor to be evaluated in clinical studies, the company claimed. Pfizer explained that protease inhibitors prevent the virus from replicating in the cell. They have been used to treat other viruses, such as HIV and hepatitis C.
“Tackling the COVID-19 pandemic requires both prevention via vaccine and targeted treatment for those who contract the virus,” said Dr. Mikael Dolsten, the company’s chief scientific officer, in a statement. “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.”
The in vitro trials suggested PF-07321332 could potentially be used in the treatment of future coronaviruses, as well, the company said. The data are expected to be shared on April 6 at the Spring American Chemical Society meeting.
“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,” Dolsten said.
He noted that the company is also working on an intravenous antiviral candidate that will serve as an 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,” Dolsten concluded.