Pfizer announced on Tuesday that it has started an early-stage clinical trial for an experimental oral antiviral drug for Covid-19.
The phase one trial of the drug, PF-07321332, is being performed in the United States, according to the New York-based firm. The drug belongs to the protease inhibitor class of drugs, and it works by blocking an enzyme that the virus needs to replicate in human cells, CNBC reported.
Other viral pathogens, such as HIV and hepatitis C, are treated with protease inhibitors.
"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," Pfizer's chief scientific officer, Mikael Dolsten, said in a press release.
The trial is taking place at the same time as Pfizer is developing PF-07304814, an intravenously administered protease inhibitor. In patients hospitalised with Covid-19, that drug is currently being tested in a phase 1b clinical trial.
Although Pfizer and German drugmaker BioNTech have an approved vaccine in the United States, health experts say the world will still need a variety of drugs and vaccines to end the pandemic.
Preclinical studies have shown that the oral drug, which is the first protease inhibitor for Covid-19 to be assessed in clinical trials, has “potent” antiviral activity against the virus, according to the company.
The drug may be used outside of hospitals for people who are newly infected with the virus because it is taken by mouth. Researchers hope that the drug will slow the progression of the disease and keep people out of the hospital.
Pfizer said it would provide more information on the drug on April 6 at the American Chemical Society’s Spring Meeting.