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.