The U.S. government has bought 600,000 doses of a new antibody drug called bebtelovimab that seems able to beat back the omicron variant, even though the medication has yet to be given the green light by the U.S. Food and Drug Administration.

The company said the contract is worth at least $720 million.

The new drug will be distributed to states for free if it receives emergency use authorization from the FDA, Health and Human Services Secretary Xavier Becerra said in a statement.

"We have more COVID-19 treatments than ever before, we are providing a billion free at-home tests, and we have enough vaccines to get everyone vaccinated and boosted," he noted. "If authorized by FDA, this purchase will add an additional 600,000 courses of treatment to our nation's 'medicine cabinet' that could help prevent severe outcomes for Americans who do get sick with COVID-19."

"We want to make sure if an American gets sick with COVID-19, they can get a treatment that works," Becerra added.

The HHS would get about 300,000 treatment courses of the new antibody drug in February and another 300,000 in March, the Associated Press reported. The medicines would be ready to ship following FDA authorization.

The omicron variant now accounts for virtually all COVID-19 cases in the United States, but two leading monoclonal antibody treatments are powerless against the variant. A GlaxoSmithKline antibody drug that does work against omicron is in short supply, as are two new antiviral pills from Pfizer and Merck.

Data suggest that bebtelovimab is effective against omicron, including the new BA.2 mutation, the AP reported.

Late last month, the FDA revoked its emergency use authorization for Regeneron's antibody drug and another one from Lilly, neither of which work against omicron.

Monoclonal antibody drugs are designed to block invading viruses. They're given intravenously or by injection early in an infection to reduce the risk of severe disease and death, the AP reported.