The San Diego company behind an experimental Ebola treatment given to two American health workers last week is now out of the drug.
In a statement posted on its website Monday afternoon, the small firm Mapp Biopharmaceutical Inc. said the last available samples of the drug, called ZMapp, were donated to a nation in West Africa.
"We have complied with every request for ZMapp that had the necessary legal/regulatory authorization," the statement reads. "It is the requestors' decision whether they wish to make public their request, acquisition, or use of the experimental drug. Any decision to use ZMapp must be made by the patients' medical team."
The White House and the U.S. Food and Drug Administration approved the experimental drug for infected Liberian doctors, according to the Liberian government.
ZMapp was scheduled for human trials in 2015 but had not been tested in humans before the current outbreak. Both American health workers treated with ZMapp are alive, though scientists say it's unclear whether the drug helped them survive. A Spanish missionary priest is also reportedly being treated with ZMapp.
ZMapp is based on antibodies drawn from animals exposed to fragments of the Ebola virus. The serum is now grown in and purified from tobacco leaves, a process that currently takes months.
Ethical questions have been raised over why Americans received the drug before Africans. But Michael Kalichman, director of UC San Diego's Research Ethics Program, says there's no easy way to determine who should receive unproven drugs first.
"If the drug works in the Americans, it will be very easy for people to say after the fact, 'Why did we save American lives and not African lives?'" said Kalichman. "But what if the drug had been used in Africans, and instead of being more effective it was actually worse? Then people would quite possibly be saying, 'Why did you try this on Africans first?'"
Other pharmaceutical companies have also sought to fast-track their experimental drugs for use in the ongoing crisis. The World Health Organization convened a panel Monday to discuss the ethics of using experimental drugs during an outbreak.
As of Monday afternoon, the Ebola outbreak has caused 1,848 infections and 1,013 deaths.
