Pfizer’s pill has been designed to target the “spine” of the SARS-CoV-2 virus and prevent it from replicating in our noses, throats, and lungs. It is classified as a “protease inhibitor.”
A notable experiment is underway at two anonymous Pfizer houses, one in the United States and the other in Belgium. Up to 60 volunteers, all of whom are healthy adults between the ages of 18 and 60, will be given the first pill engineered specifically to stop Covid-19.
If the trial proves to be a success, a home remedy for Covid-19 may be available later this year. Prime Minister Boris Johnson of the United Kingdom, who last week announced the establishment of a “Antivirals Taskforce” to invest in such items, would undoubtedly be checking his text messages for early updates.
The molecule in question is PF-07321332, a one-of-a-kind antiviral. It was developed as a “protease inhibitor” to attack the SARS-CoV-2 virus’s “spine” and prevent it from replicating in our noses, throats, and lungs. Protease inhibitors were the drugs that stopped HIV from spreading in the UK and around the world.
Penny Ward, a visiting professor of pharmaceutical medicine at King’s College London and a pioneer in the production of Tamiflu, an antiviral that combats seasonal and pandemic flu, said, “If they have moved to this stage, they will be quietly optimistic… The question will be about how the drug is tolerated… They will be clapping like clappers.”
Dafydd Owen, director of medicinal chemistry at Pfizer, told a private symposium of the Division of Medicinal Chemistry last month that the antiviral pill was created from the ground up during the current pandemic.
In late July 2020, the first seven milligrams of the compound – about the size of a raindrop – were produced. They’d made 100 grams by the end of October. They had more than a kilogram in the bag after just two weeks. It took 210 researchers to complete, according to Owen.
Pfizer is keeping the specifics of the lab experiments under wraps, but it claims to have demonstrated “potent in vitro antiviral activity against SARS-CoV-2,” as well as activity against other coronaviruses, increasing the possibility of a cure for the common cold and possible pandemic risks.
In a statement released last month, Mikael Dolsten, chief scientific officer and president of worldwide science, development, and medical at Pfizer, said, “We have designed PF-07321332 as a potential oral therapy that could be prescribed at the first sign of infection, without requiring patients to be hospitalized or in critical care.”
According to Ward, Pfizer’s scientists will have most likely demonstrated the drug’s “potent” anti-SARS-CoV-2 activity in a laboratory setting by testing it on infected human tissue cultures, including lung tissue. “Once you know it works in vitro, it’s all about establishing tolerance in animals and then humans,” she explained.
The Sunday Telegraph has acquired copies of the documents given to participants in the first human trials, which are currently underway.
“To date, the study drug has not been administered to humans,” according to the documents, which were formally approved on February 8th of this year.
“The safety of the study drug has been studied in animals. In these animal studies, no significant risks or safety events of concern were identified, and the study drug did not cause side effects at any of the dose levels that will be used in clinical studies.”
Many who have signed up for the trial will have a busy few months ahead of them. The trial will be divided into three phases and will last 145 days, with an additional 28 days for “screening and dosing.” There will be many overnight stays for all participants.
The briefing documents state, “You are here today as a participant in a drug research study sponsored by Pfizer Incorporated… Taking part in this study is voluntary… If you are not completely honest about your health history, you may be harmed by being in this study.”
The aim of the “randomized, double-blind, placebo-controlled, single- and multiple-dose escalation study” is to see how well or poorly different dosing regimens are handled in humans while the active compound is kept in the body.
The antiviral PF-07321332 will be given in combination with low doses of ritonavir, which is used to treat HIV. It works as a “booster” to raise the amount of PF-07321332 in the blood of participants.