Drugmaker Merck has said that its experimental pill for people sick with COVID-19 reduced hospitalisations and deaths by half, in a potential leap forward in the global fight against the pandemic.

If cleared by regulators, it would be the first pill shown to treat COVID-19.

The company said it will soon ask health officials in the US and around the world to authorise the pill’s use. A decision from the US Food and Drug Administration could come within weeks after that, and the drug, if approved, could be distributed quickly soon afterward.

A pill taken at home would ease pressure on hospitals and could also help curb outbreaks in poorer and more remote corners of the world that don’t have access to the more expensive infusion therapies.

Merck and its partner Ridgeback Biotherapeutics said early results showed patients who received the drug, molnupiravir, within five days of COVID-19 symptoms had about half the rate of hospitalisation and death as those who received a dummy pill.

The study tracked 775 adults with mild-to-moderate COVID-19 who were considered high risk for severe disease because of health problems such as obesity, diabetes or heart disease. The results have not been reviewed by outside experts, the usual procedure for vetting new medical research.

Among patients taking molnupiravir, 7.3 per cent were either hospitalised or died at the end of 30 days, compared with 14.1 per cent of those getting the dummy pill. After that time period, there were no deaths among those who received the drug, compared with eight in the placebo group, according to Merck.

The results were so strong that an independent group of medical experts monitoring the trial recommended stopping it early.

Company executives said they plan to submit the data to the FDA in the coming days.

COVID vaccines still important

Experts stressed the continued importance of vaccines for controlling the pandemic, given that they help prevent transmission and also reduce the severity of illness in those who do get infected.

White House coronavirus coordinator Jeff Zients said that vaccination will remain the government’s main strategy for controlling the pandemic. "We want to prevent infections, not just wait to treat them when they happen," he said.

Dr. Anthony Fauci, the government's foremost authority on infectious diseases, called the results from Merck "very good news".

Health experts, including Fauci, have long called for a convenient pill that patients could take when COVID-19 symptoms first appear.

Merck only studied its drug in people who were not vaccinated. But FDA regulators may consider authorizing it for broader use in vaccinated patients who get breakthrough COVID-19 symptoms.

Andrew Pekosz of Johns Hopkins University predicted vaccines and antiviral drugs would ultimately be used together to protect against the worst effects of COVID-19.

"These shouldn’t be seen as replacements for vaccination — the two should be seen as two strategies that can be used together to significantly reduce severe disease," said Pekosz, a virology specialist.

The U.S. government has committed to purchasing enough pills to treat 1.7 million people, assuming the FDA authorises the drug. Merck said it can produce pills for 10 million patients by the end of the year and has contracts with governments worldwide.

The results reported Friday included patients across Latin America, Europe and Africa.