STORY HIGHLIGHTS
Ebola drug ZMapp was developed by a
company based in San Diego
Other companies have also been working to
develop treatments for Ebola
It's unclear whether the drug will be
administered to other Ebola patients

Two American missionary workers infected with the deadly Ebola virus were given an
experimental drug that seems to have saved their
lives.
Dr. Kent Brantly was given the medication,
ZMapp, shortly after telling his doctors he
thought he would die, according to a source
familiar with his case. Within an hour, doctors say
his symptoms -- labored breathing and a
widespread rash -- dramatically improved. Nancy
Writebol, another missionary working with
Samaritan's Purse, received two doses of the
medication and has also shown significant
improvement, sources say.
As there is no proven treatment and no vaccine
for Ebola, this experimental drug is raising lots of
questions.

Who makes the drug?

The drug was developed by the biotech firm Mapp
Biopharmaceutical Inc., which is based in San
Diego. The company was founded in 2003 "to
develop novel pharmaceuticals for the prevention
and treatment of infectious diseases, focusing on
unmet needs in global health and biodefense,"
according to its website .
Mapp Biopharmaceutical has been working with
the National Institutes of Health and the Defense
Threat Reduction Agency, an arm of the military
responsible for weapons of mass destruction, to
develop an Ebola treatment for several years.

Are there other experimental Ebola drugs out
there?

Yes. In March, the NIH awarded a five-year $28
million grant to establish a collaboration between
researchers from 15 institutions who were
working to fight Ebola.
"A whole menu of antibodies have been identified
as potentially therapeutic, and researchers are
eager to figure out which combinations are most
effective and why," a news release about the
grant said.
Tekmira, a Vancouver-based company that has a
$140 million contract with the U.S. Department of
Defense to develop an Ebola drug, began Phase 1
trials with its drug in January. But the FDA
recently halted the trial, asking for more
information.
At least one potential Ebola vaccine has been
tested in healthy human volunteers, according to
Thomas Geisbert, a leading researcher at the
University of Texas Medical Branch. And last
week, the NIH announced a safety trial of another
Ebola vaccine will start as early as September.

How does ZMapp work?

Antibodies are proteins used by the immune
system to mark and destroy foreign, or harmful,
cells. A monoclonal antibody is similar, except
it's engineered in a lab so it will attach to specific
parts of a dangerous cell, according to the Mayo
Clinic , mimicking your immune system's natural
response. Monoclonal antibodies are used to treat
many different types of conditions.
This medicine is a three-mouse monoclonal
antibody, meaning that mice were exposed to
fragments of the Ebola virus and then the
antibodies generated within the mice's blood were
harvested to create the medicine.


Why did American missionary workers get the
drug?

Many have asked why these two workers received
the experimental drug when so many -- around
1,600 -- others in West Africa also have the virus.
Samaritan's Purse reached out to an NIH
scientist who was on the ground in West Africa,
according to the National Institute of Allergy and
Infectious Diseases. "The scientist was able to
informally answer some questions and referred
them to appropriate company contacts to pursue
their interest in obtaining experimental product,"
NIAID said.
The World Health Organization says it was not
involved in the decision to treat Brantly and
Writebol. Both patients had to give consent to
receive the drug, knowing it had never been tested
in humans before.
The process by which the medication was made
available to the American patients may have
fallen under the U.S. Food and Drug
Administration's "compassionate use" regulation,
which allows access to investigational drugs
outside clinical trials.

Did doctors know it would work?

No. The drug had shown promise in primates, but
even in those experiments, just eight monkeys
received the treatment. In any case, the human
immune system can react differently than
primates', which is why drugs are required to
undergo human clinical trials before being
approved by government agencies for widespread
use.
The two Americans' cases will be studied further
to determine how the drug worked with their
immune systems.

Will the drug be made available to other Ebola
patients?

It's unclear. Doctors "cannot start using untested
drugs in the middle of an outbreak, for various
reasons," World Health Organization spokesman
Gregory Hartl said.
Dr. Anthony Fauci, director of the National
Institute of Allergy and Infectious Diseases, says
scientists have to be careful about assuming this
drug will work in other patients as it appears to
have worked in Brantly.
"Having worked with administering antibodies for
people for a really long time, that would be
distinctly unusual," he told CNN. "As we all know
in medicine ... you have to withhold judgment."

Does the company have more vials of the drug?

The company has very few doses ready for
patient use, Fauci told CNN. "Apparently the
company is trying to scale up, (but) it's not easy
to scale up to very large number of doses."

Who paid for the drug and how much did it cost?

We don't know. Samaritan's Purse covered the
cost of Brantly and Writebol's evacuations but did
not pay for the drug, according to a spokesman.
When a patient gets an experimental drug, the
drug company can donate the product under
compassionate use. Mapp Biopharmaceutical Inc.
might have done that in this case.
Health insurance companies typically do not pick
up the tab for treatments that have not been
approved by the FDA. But they would usually
cover the cost of any doctor fees associated with
giving the drug and any costs associated with
monitoring how the drug is working.


Would this drug stop the Ebola epidemic?

If it were widely available, it certainly couldn't
hurt. An effective Ebola drug could help doctors
treat the deadly virus, which is killing about 60%
of the people infected in West Africa. But a
vaccine would be a much more effective tool in
stopping this, and future, epidemics.
Vaccines are given to healthy people to prevent
them from ever becoming infected. One challenge
with Ebola, experts say, is that companies don't
believe they could make much money from
developing a vaccine, so few companies show
interest.