Pfizer Inc. said its COVID-19 pill reduced hospitalizations and deaths in high-risk patients by 89%, a result that has the potential to upend how the disease caused by the coronavirus is treated and alter the course of the pandemic.

The drugmaker said in a statement on Friday that it was no longer taking new patients in a clinical trial of the treatment "due to the overwhelming efficacy,” and planned to submit the findings to U.S. regulatory authorities for emergency authorization as soon as possible.

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