Merck on Friday said it will seek emergency approval of an antiviral pill to treat COVID-19 after it significantly cut the risk of bad outcomes in clinical trials.

The New Jersey-based drugmaker said the drug, molnupiravir, cut the risk of hospitalization or death in half in high-risk patients with mild to moderate illness.

If authorized for use, it would be a groundbreaking treatment. Pills are easy to take and can reach a wider audience than monoclonal antibodies, an effective treatment in high demand.

Merck said it stopped the trial early in consultation with the Food and Drug Administration because the results were positive.

“With the virus continuing to circulate widely, and because therapeutic options currently available are infused and/or require access to a health care facility, antiviral treatments that can be taken at home to keep people with COVID-19 out of the hospital are critically needed,” said Wendy Holman, chief executive officer of Ridgeback Biotherapeutics, a Miami-based company that worked with Merck.

The pills’ efficacy was lower than monoclonal antibodies, but those drugs are expensive and often given intravenously, making them a labor-intensive effort for overtaxed hospitals.

“With these compelling results, we are optimistic that molnupiravir can become an important medicine as part of the global effort to fight the pandemic and will add to Merck’s unique legacy of bringing forward breakthroughs in infectious diseases when they are needed most,” Merck CEO and President Roger M. Davis said.

Two other groups, Pfizer and Atea Pharmaceuticals-Roche, are working on pill-form treatments.