Pfizer is testing new anti-COVID-19 pill. How does it work?
Biopharmaceutical company Pfizer on Monday said that it has started middle-to-late stage clinical trial of an anti-COVID-19 pill to tackle the disease. The trial aims to assess the safety and efficacy of the drug in terms of preventing COVID-19 from progressing into a severe infection. Pfizer had started developing the drug, called PF-07321332, in March 2020. Here are more details.
How does the pill work?
Pfizer's pill is an oral antiviral drug that could help prevent a severe form of COVID-19. It is essentially a protease inhibitor, which has been shown to successfully shut down the replication machinery of the virus SARS-CoV-2 in lab testing. It is expected to be effective only in the early stages of COVID-19 since as the disease becomes severe, the virus largely stops replicating.
What will the trial include?
The trial will include 2,660 healthy participants aged 18 or older living in the same household as a symptomatic infected individual. It will be a randomized, double-blind, placebo-controlled study. The participants will either be administered a combination of PF-07321332 and ritonavir (a repurposed HIV medication) or a placebo drug twice a day for five or 10 days.
Early trial results show pill is 'safe' and 'tolerable'
"Results from the Phase I clinical trial demonstrated that PF-07321332 was safe and well-tolerated," Pfizer said in a statement announcing the trial. The aim is to come up with a drug that can potentially be prescribed to people at the first sign of COVID-19 infection.
'If successful, pill could stop virus early'
Pfizer's Chief Scientific Officer and President, Worldwide Research, Development and Medical, Mikael Dolsten said, "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." Dolsten highlighted the drug's importance in light of the emergence of new variants.
When will the drug be available?
The Pfizer pill could become a game-changer if clinical trials prove its effectiveness. Reports suggest the drug could be available in the market by the end of this year. Pfizer had earlier planned to initiate roll-out by the end of 2021.
Several companies working on similar oral antivirals
Notably, Pfizer is not alone in the race to develop oral antivirals against COVID-19. Merck & Co. and Ridgeback Biotherapeutics have also developed a similar drug called Molnupiravir. Roche and Atea Pharmaceuticals have developed another oral antiviral known as AT-527. Pfizer's Dolsten said, "Tackling the virus will require effective treatments for people...exposed to...the virus, complementing the impact that vaccines have had."