The U.S. Justice Department, in a filing to the New Orleans-based 5th U.S. Circuit Court of Appeals, called the April 7 order by U.S. District Judge Matthew Kacsmaryk "abrupt and profoundly disruptive." It added that mifepristone's safety is "amply supported by a record developed over decades of safe and effective use" around the world.
The 5th Circuit is preparing to hear May 17 arguments on the matter after the U.S. Supreme Court last week put on hold Kacsmaryk's order. The high court's action preserved broad access to mifepristone while the litigation proceeds.
The Justice Department said Kacsmaryk's order was unprecedented in overturning a drug approval by the U.S. Food and Drug Administration based on a disagreement with the agency's determination that the drug is safe. The FDA, the U.S. agency that signs off on the safety of food products, drugs and medical devices, approved mifepristone in 2000.
"The district court's order would thwart FDA's scientific judgment and profoundly harm women who rely on mifepristone as an alternative to more burdensome and invasive surgical abortions," the Justice Department wrote.
The department said the plaintiffs - anti-abortion groups led by the recently formed Alliance for Hippocratic Medicine and four anti-abortion doctors who sued the FDA in November - had no basis to challenge the approval because they were not harmed by it and brought their lawsuit much too late.
Biden's administration is defending the drug in the face of mounting abortion bans and restrictions enacted by Republican-led states since the Supreme Court in June 2022 overturned the landmark 1973 Roe v. Wade decision that had legalized the procedure nationwide.
Major drug companies have come out against Kacsmaryk's order, saying it would put the whole pharmaceutical industry at risk by calling into question every FDA approval and would discourage new drug development.
Danco Laboratories, which manufactures the brand-name version of the drug, was due to make a separate filing with the 5th Circuit.
Mifepristone is taken with another drug called misoprostol to perform medication abortion, which accounts for more than half of all U.S. abortions.
The challengers contend that the FDA failed to fully evaluate the pill's safety and then removed critical safeguards on what they call a dangerous drug.
Lawyers for the plaintiffs did not immediately respond to a request for comment on Wednesday. They are due to file a response by May 8.
A panel of three 5th Circuit judges is scheduled to hear arguments on whether to uphold Kacsmaryk's order. The 5th Circuit has a conservative reputation, with 12 of its 16 active judges appointed by Republican presidents. The panel's decision will be subject to appeal to the full 5th Circuit and then potentially to the Supreme Court, which has a 6-3 conservative majority.
By filing their lawsuit in Amarillo, the plaintiffs ensured the case would go before Kacsmaryk, a former Christian legal activist appointed to the bench by former President Donald Trump. Kacsmaryk had a long track record of opposing abortion before the U.S. Senate confirmed him in 2019 to a life-tenured position as a federal judge.
Shortly after Kacsmaryk's order, another federal judge in Spokane, Washington issued an order barring the FDA from imposing any new restrictions on the distribution of mifepristone in 17 states. That order remains in effect and would conflict with any future order banning or restricting the drug.