Pfizer’s At-Home Pill for Treating COVID Could Be Ready By the End of the Year

Last month, multinational pharmaceutical company Pfizer Inc. announced that it had begun human safety testing of a new pill to treat the coronavirus. If successful, the at-home oral drug could be prescribed and used as a preventative measure or at the first signs of illness from COVID-19: blocking the SARS-CoV2 virus from replicating and preventing patients from becoming more sick. 

Mikael Dolsten, Pfizer’s Chief Scientific Officer, told Bloomberg at the time that the study might yield results in as little as a few weeks. This week, company chairman and CEO Albert Bourla suggested that the Pfizer pill may well be available for public consumption before the end of the year.

“If all goes well, and we implement the same speed that we are, and if regulators do the same … I hope that by the end of the year [it will be available for use],” Bourla told CNBC on Tuesday—noting that an orally administered drug that could be taken at home, rather than at a hospital, would be a “game changer.” Dolsten described it in the exact same terms.

The active ingredient of the drug, which is currently being called PF-07321332, fights the SARS-CoV2 virus by binding to a viral enzyme called a “protease”, preventing the virus from reproducing in cells and thus blocking it from spreading throughout a patient’s body.

It is the first orally administered compound to enter clinical trials that targets the virus’ main protease—and researchers hope this will help it prevent patients from becoming severely ill and needing to be hospitalised, mitigating the impact of the virus on the individual and in turn reducing pressure on the health system. 

The drug is currently in Phase 1 trials, but Dolsten suggested that if things continue to run smoothly Pfizer could begin a much larger combined Phase 2-Phase 3 trial early in the second quarter of the year, potentially allowing the company to apply for emergency-use authorization from the Food and Drug Administration by the end of 2021.

Moreover, while initial testing focuses specifically on people with early infections, Pfizer also plans to explore whether the drug is effective in protecting healthy people who have been exposed to the coronavirus—family members or roommates of sick patients, for example.

Pfizer is also working on another antiviral drug that would be given intravenously to hospitalized virus patients. Together, Dolsten said, “the two have the potential to create an end to end treatment paradigm,” working alongside vaccination in cases where disease still occurs.

“For the foreseeable future, we will expect to see continued outbreaks from COVID-19,” Charlotte Allerton, Pfizer’s head of medicine design, told Chemical & Engineering News. “And therefore, as with all viral pandemics, it’s important we have a full toolbox on how to address it.”

While Pfizer isn’t the only pharmaceutical company working on an anti-COVID pill, it is the one that’s showing the most promise. Merck & Co., another major multinational pharmaceutical company, was recently forced to halt development of two experimental drugs for patients hospitalized with COVID-19, and limit a third to people suffering from a milder form of the disease, after trials failed to show a meaningful benefit in preventing hospitalizations and deaths.

Nonetheless, infectious disease experts and public health officials remain eager to see more data on the drug’s efficacy among non-hospitalized patients. Rajesh Gandhi, an infectious disease physician at Massachusetts General Hospital and Harvard Medical School, told Bloomberg that “we still certainly need an oral antiviral to treat COVID-19.”

Follow Gavin on Twitter