US pharmaceutical company Pfizer on Tuesday asked regulators to authorize its Covid pill after it was shown to cut hospitalization or death by nearly 90 percent among newly-infected high risk patients.
The move comes a few weeks after Merck also approached the Food and Drug Administration seeking a green light for its antiviral capsule against the coronavirus.
Experts see the oral medications as an invaluable addition to vaccines in the fight to end the pandemic.
"With more than five million deaths and countless lives impacted by this devastating disease globally, there is an urgent need for life-saving treatment options," Pfizer CEO Albert Bourla said in a statement.
"We are moving as quickly as possible in our effort to get this potential treatment into the hands of patients."
Pfizer is seeking an emergency use authorization (EUA) on the basis of positive interim results from a mid-to-late stage clinical trial of hundreds of people, which enrolled Covid-positive non-hospitalized adults at high risk of progression to severe disease.
The data showed an 89 percent reduction in Covid hospitalizations or death when the treatment started within three days of symptom onset, with no deaths in the treatment group. Similar results were seen within five days of symptom onset.
Side-effects occurred in about one-in-five patients in both the treatment and placebo groups, and were mild in intensity.
The treatment is given over five days.
Pfizer has said it will deliver 180,000 courses of its Paxlovid pill this year and at least 50 million by next year.
On Tuesday it announced a deal with the UN-backed Medicines Patent Pool (MPP) to sub-licence production for supply in 95 low- and middle-income nations covering around 53 percent of the world's population.
Paxlovid is a combination of a new molecule, PF-07321332, and HIV antiviral ritonavir.
Both belong to a class of antivirals called "protease inhibitors," which block the action of an enzyme critical to viral replication.
President Joe Biden's administration is set to announce that it is purchasing 10 million courses of the pill, the Washington Post reported.
The US is also buying 3.1 million courses of the Merck pill, Molnupiravir.
Given the timeline between application for an EUA and subsequent authorization, it could be available by late this year or early next.