being developed for Ebola, Saphire indicated that health authorities have good reasons to bring Mapp Bio’s drug to the forefront of efforts to get the outbreak in West Africa under control.
Some other treatments have had to be administered within 30 minutes of exposure to the virus to be effective, she said. But in tests with monkeys, she said ZMapp was administered as long as three days after the animals were infected with a very high dose of Ebola virus—and all of the monkeys survived. Saphire said the antibody cocktail even showed some effect on monkeys that were treated several days later, after they had developed Ebola symptoms.
“The antibodies also looked really good from a compassionate use and humanitarian standpoint,” Saphire said. “We know how to make antibodies, we know how they work, and we know there is often less danger of toxicity compared with other types of drugs.”
Liberia said Monday it would get doses of ZMapp to give to two sick doctors, making them the first Africans to receive the scarce treatment as the death toll continues to mount. According to the latest report on the CDC website, health authorities have confirmed at least 1,069 deaths from Ebola in Guinea, Liberia, Nigeria, and Sierra Leone.
The San Diego biotech also provided ZMapp for a Spanish priest, Miguel Pajares, who died in a Madrid hospital five days after he was airlifted from Liberia—where he also was caring for Ebola patients.
In a statement posted on its website earlier this week, Mapp Bio said the available supply of its still-experimental drug therapy has been exhausted. The company has it would take months to produce even modest quantities.
Time is a factor because the Ebola virus causes an extremely virulent disease, which leads to death in 25 to 90 percent of the cases. The virus spreads by direct contact with the blood or other bodily fluids of an infected person.
Meanwhile, a Canadian drug developer, Tekmira Pharmaceuticals, has developed an experimental drug treatment that uses RNA interference to silence genes in the Ebola virus. The Vancouver, BC-based company says it is looking into ways that its experimental Ebola treatment might be used to combat the outbreak in West Africa, even though the drug hasn’t been formally cleared by the various regulatory agencies. Another RNA drug developer, Cambridge, MA-based Sarepta Therapeutics, has said it also has an experimental Ebola drug that could be deployed if regulators would allow it. The company discontinued work on the drug in 2012 amid hangups with defense grants that had been funding the program.
In the most recent statement on its website, Mapp Bio says: “We have complied with every request for ZMapp that had the necessary legal/regulatory authorization. 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. Drug has been provided at no cost in all cases.”
