An experimental Ebola drug has been used to treat two American aid workers and a Spanish missionary priest, the latter dying yesterday. Some questions and answers about the Ebola drug:
What is this drug?
Called ZMapp, it is a cocktail of specially engineered antibodies designed to target and inactivate the Ebola virus.
What do we know about whether it works?
Very little. Various antibodies have been tested in small numbers of monkeys, but not people. In one study, 43 percent of treated monkeys survived when the drug was given after the animals showed symptoms. The manufacturer, Mapp Biopharmaceutical, is developing a combination of three antibodies that seemed most promising in those animal studies.
Why isn’t ZMapp being tested more widely to find out if it works in people?
There’s not enough available. The antibodies are grown inside tobacco plants, and then extracted and purified, a slow process. US officials have estimated that only a modest amount could be produced in two or three months, unless some way to speed production is found.
How were the Americans and Spanish priest chosen to get some of those limited doses, rather than Africans?
The international relief organization Samaritan’s Purse and Emory University Hospital requested that the manufacturer provide some of the drug for the two Americans, and the manufacturer agreed. As for the Spanish missionary priest, it wasn’t clear exactly how Spanish officials obtained a dose that apparently was in Geneva. The priest also was infected in Liberia and died at a Madrid hospital.
Typically, the Food and Drug Administration doesn’t regulate shipments of unapproved drugs for emergency use in individual patients outside the US
Are any other drugs in the pipeline?
Canada’s Tekmira Pharmaceuticals Corp. is developing a drug that targets Ebola’s genetic material. The FDA had halted a small safety study with questions about a reaction in healthy volunteers. Last week, Tekmira announced that FDA had modified its restriction, clearing a roadblock to possible experimental use in infected patients; the company said at the time that it was “carefully evaluating options.”
A handful of other companies are in earlier stages of drug development; a possible vaccine to prevent the disease is expected to begin first-stage safety studies sometime in the fall.