NEW YORK - Pfizer has begun mid-to-late stage trials of an oral COVID-19 drug designed to prevent infection in those who have been exposed to the coronavirus.
The drugmaker said Monday it has launched Phase 2/3 of a global clinical trial that aims to enroll up to 2,660 healthy adults who live in the same household as an individual with a confirmed, symptomatic COVID-19 infection.
"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," Dr. Mikael Dolsten, Pfizer’s chief scientific officer and president of worldwide research, development and medical, said in a statement.
The Phase 2/3 trial of the drug is a randomized, double-blind, placebo-controlled study. Participants will be randomly assigned to receive the oral drug, referred to as PF-07321332, along with a low dose of the anti-HIV drug ritonavir, or receive an oral placebo. The participants will take the drug twice daily for five or 10 days.
The treatment is a protease inhibitor, which is a type of antiviral drug that inhibits the replication of certain cells and viruses, including HIV. Receiving Pfizer’s drug with ritonavir is expected to help slow the breakdown of PF-07321332 in order for it to remain active in the body for longer.
NEW YORK, NY - JULY 22: Pfizer Inc. signage is seen on July 22, 2020 in New York City. Pfizer and German biotechnology firm BioNTech have agreed to supply the U.S. government with 100 million doses of coronavirus vaccine under a $1.95 billion deal. (
Pfizer’s treatment was specifically designed to be administered orally so that it can potentially be prescribed at the first sign of infection or at first awareness of possible exposure to someone with COVID-19.
The study aims to assess both the safety and efficacy for the prevention of COVID-19 and symptoms through day 14.
Pfizer’s oral antiviral drug was safe and well-tolerated during the Phase 1 clinical trial, which first began in March, the company said.
To date, there is no oral drug currently approved for post-exposure or pre-emptive treatment for COVID-19.
Last week, a booster shot of Pfizer’s COVID-19 vaccine was approved by U.S. health officials for those 65 and older, adults with underlying health conditions and people at increased risk of being exposed to the virus because of their jobs.
This story was reported from Cincinnati.