Pfizer Inc. reported that its Covid-19 pill reduced hospitalizations and deaths in high-risk patients by 89%, a result that has the potential to change the way coronavirus disease is treated and alter the course of the pandemic. Shares soared in pre-opening trading.

The pharmaceutical company said on Friday, November 5, in a statement that it stopped accepting new patients in a clinical trial of the treatment "due to the overwhelming efficacy" and that it planned to present the results to US regulatory authorities to obtain an emergency authorization as soon as possible. . Pfizer shares were up 11% as of 6:52 a.m. ET in New York.

The results mean that there are now two promising candidates for treating COVID-19 patients in the early stages of the disease. Last month, Merck & Co. and its partner Ridgeback Biotherapeutics LP presented their experimental pill to regulators after a study showed that it cut the risk of becoming seriously ill or dying in half in patients with mild to moderate Covid-19.

A pill that could be taken at home at the first symptom is a crucial tool in managing the Covid-19 crisis around the world, provided it is widely available. A Pfizer spokesman said the pill will be submitted to other regulatory agencies shortly after the application is filed in the United States.

In Pfizer's trial of 1,219 unvaccinated adults, five days of treatment with its drug dramatically reduced the rate of hospitalization when it was started within three to five days after symptoms began, the company reported.

The drug, Paxlovid, binds to an enzyme called protease to prevent the virus from replicating. Some HIV medications work in a similar way.